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SUMMARY:*Leading Talk* Chiral methods at the electroweak scale
DTSTART;VALUE=DATE-TIME:20150702T123000Z
DTEND;VALUE=DATE-TIME:20150702T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70667@agenda.infn.it
DESCRIPTION:Speakers: Oscar Cata (LMU Munich)\nAfter the discovery of the
Higgs particle at the LHC in its first run\, one of the priorities of the
second run will be to ascertain its nature and understand the dynamics tha
t trigger the breaking of electroweak symmetry. However\, in order to sear
ch for deviations from a standard Higgs one needs a framework that goes be
yond the Standard Model. In this talk I will discuss in which way techniqu
es borrowed from chiral dynamics can be used to provide such a general fra
mework and will point out which processes are most sensitive to nonstandar
d Higgs signatures.\n\nhttps://agenda.infn.it/event/7897/contributions/706
67/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70667/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extracting neutron polarizabilities from Compton scattering on qua
si-free neutron in gamma d->gamma n p
DTSTART;VALUE=DATE-TIME:20150702T155000Z
DTEND;VALUE=DATE-TIME:20150702T160500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70666@agenda.infn.it
DESCRIPTION:Speakers: Berhan Demissie (George Washington University\, Wash
ington)\nCompton scattering processes are ideal to study electric and magn
etic dipole polarizability coeffcients of nucleons [1]. These fundamental
quantities parametrize the response to a monochromatic photon probe. In th
is work\, the inelastic channel γd → γnp is treated in χEFT\, with a
focus on the NQFP - neutron quasi-free peak - kinematic region. In this re
gion\, the momentum of the outgoing proton is small enough that it is cons
idered to remain at rest. This provides access to the Compton scattering p
rocess γn → γn from which the neutron scalar polarizabilites α and β
are extracted. Using χEFT\, differential cross-sections\, d^3σ/dE_ndΩ
γ Ωn\, in the photon energy range of 200-400 MeV are computed. The bigg
est contribution comes from the impulse approximation\, with small correct
ions stemming from final state interaction\, meson exchange currents and r
escattering. A new extraction of neutron polarizabilities from a two-param
eter fit to the Kossert et al. [2] data taken at MAMI in 2002 is presented
. Previously\, the experiment was designed and the data analysed based on
a theoretical model [3] that computed the NQFP differential cross-sections
. The re-analysis of this data in a consistent\, model independent framewo
rk - χEFT - provides reliable extraction of polarizabilies with controlle
d uncertainties.\n\nThis work is supported in part by the US Department of
Energy under grant DE-FG02-\n95ER-40907.\n\nReferences\n1. H. W. Grießha
mmer\, J. A. McGovern\, D. R. Phillips\, G. Feldman\, Prog. Part. Nucl. Ph
ys. 67\, 841 (2012).\n2. K. Kossert et al.\, Phys. Rev. Lett. 88\, 162301
(2002).\n3. M. I. Levchuk\, A. I. L’vov\, and V. A. Petrun’kin\, Few-B
ody Syst. 16\, 101 (1994).\n\nhttps://agenda.infn.it/event/7897/contributi
ons/70666/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70666/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral two-nucleon dynamics\, analyticity and dispersion relations
DTSTART;VALUE=DATE-TIME:20150630T123000Z
DTEND;VALUE=DATE-TIME:20150630T124500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70665@agenda.infn.it
DESCRIPTION:Speakers: Ashot Gasparyan (Ruhr University\, Bochum)\nNucleon-
nucleon interaction is studied using relativistic form of the chiral Lagr
angian. Partial-wave amplitudes are computed in chiral perturbation theory
at next-to-next-to-leading order in the subthreshold region. The most gen
eral constraints set by analyticity and unitarity are implemented to extra
polate the amplitudes into the physical region using the method developed
in Refs. [1\,2]. Empirical phase shifts are described up to laboratory ene
rgies T_{lab} approx 250 MeV. The issues related with renormalization and
convergence of perturbation theory are investigated.\n\n[1] A. Gasparyan\,
M. F. M. Lutz\, Nucl. Phys. A848 (2010) 126-182.\n[2] A. M. Gasparyan\, M
. F. M. Lutz and E. Epelbaum\, Eur.Phys. J. A 49\, 115 (2013)\n\nhttps://a
genda.infn.it/event/7897/contributions/70665/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70665/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The K Cascade production in coupled channel chiral models up to ne
xt-to-leading order.
DTSTART;VALUE=DATE-TIME:20150702T151000Z
DTEND;VALUE=DATE-TIME:20150702T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70664@agenda.infn.it
DESCRIPTION:Speakers: Albert Feijoo (University of Barcelona)\nThe meson-b
aryon interaction in the S=-1 sector is studied by means of a chiral SU(3)
Lagrangian up to next-to-leading order\, implementing unitarization in co
upled channels. The parameters of the Lagrangian have been fitted to a lar
ge set of experimental data in two-body channels. We focused on K- p --> K
Cascade reactions because they show the strongest sensitivity to the next
-to-leading order (NLO) coefficients\, due to the zero tree level contribu
tion of the leading-order terms. As we will see\, the leading order Lagran
gian\, even taking into account the contributions via unitaritzation\, can
not build enough strength to reproduce the experimental data. Thus\, NLO
corrections are absolutely mandatory in the K Cascade production channels.
In order to improve the the description of the total and differential K-
p --> K Cascade cross sections\, and to analyse the accuracy and stabilit
y of the obtained NLO parameters\, phenomenological contributions of massi
ve high spin resonances in K Cascade channels have been introduced and stu
died. The resulting K Cascade interaction has been also applied to study o
f the decay process $Lambda_b -> J/Psi K Xi\, which can be studied by the
LHCb Collaboration\n\nhttps://agenda.infn.it/event/7897/contributions/706
64/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70664/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Resonances in the electroweak chiral lagrangian
DTSTART;VALUE=DATE-TIME:20150702T130000Z
DTEND;VALUE=DATE-TIME:20150702T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70663@agenda.infn.it
DESCRIPTION:Speakers: Ignasi Rosell (Universidad CEU Cardenal Herrera\, Va
lencia)\nWe study strongly coupled models of electroweak symmetry breaking
with a light Higgs boson. We use a resonance effective Lagrangian with bo
sonic massive resonances together with the Standard Model degrees of freed
om\, including a light Higgs. We consider constraints from the phenomenolo
gy and from the assumed high-energy behavior of the underlying theory. Thi
s resonance effective theory can be used to estimate the low-energy consta
nts (LECs) of the Electroweak Effective Theory (Electroweak Chiral Lagrang
ian) in terms of resonance parameters and to make predictions of low-energ
y observables like\, for instance\, the oblique parameters. Note that the
theoretical framework is completely analogous to the Resonance Chiral Theo
ry description of QCD at GeV energies.\n\nhttps://agenda.infn.it/event/789
7/contributions/70663/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70663/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hadronic uncertainties and isospin violation in supersymmetric dar
k matter models
DTSTART;VALUE=DATE-TIME:20150630T132000Z
DTEND;VALUE=DATE-TIME:20150630T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70662@agenda.infn.it
DESCRIPTION:Speakers: Lewis Tunstall (University of Bern)\nCurrent limits
from dark matter direct-detection experiments place a powerful constraint
on the parameter space of the Minimal Supersymmetric Standard Model (MSSM)
. The interpretation of these limits\, however\, depends sensitively on t
he hadronic uncertainties associated with the scattering of supersymmetric
dark matter particles off nucleons. For spin-independent scattering\, we
review the role of chiral perturbation theory in the determination of the
se hadronic uncertainties\, and quantify the amount of isospin violation w
ithin several simplified versions of the MSSM. In each case\, we identify
parameter-space configurations that produce (almost) vanishing cross sect
ions and examine the complementarity of constraints due to direct-detectio
n\, flavour\, and collider experiments. In the vicinity of these so-calle
d blind spots\, we find that isospin violation is much larger than typical
ly expected in the MSSM.\n\nhttps://agenda.infn.it/event/7897/contribution
s/70662/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70662/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pseudoscalar decays into lepton pairs from rational approximants
DTSTART;VALUE=DATE-TIME:20150630T151000Z
DTEND;VALUE=DATE-TIME:20150630T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70661@agenda.infn.it
DESCRIPTION:Speakers: Pablo Sanchez Puertas (Johannes Gutenberg University
\, Mainz)\nPseudoscalar-meson decays (π0\, η\, η ) into lepton pairs (e
+e−\, µ+µ−) are unique in its kind as they probe the neutral pseudos
calar meson structure in the whole energy-range. This structure\, which is
encoded in the doubly virtual transition form factor (TFF) governing thei
r interactions with two photons\, needs a complete energy description. In
this work\, we identify the relevant energy regimes related to this proces
ses and propose the use of rational approximants for describing the TFF\,
emphasizing the correct low- energy description and high-energy implementa
tion. Motivated by the range spanned by the pseudoscalar masses\, we will
discuss the use of different rational approximants: Pade' approximants\, w
hich have been successfully used in the past [1\,2]\, its necessary extens
ion to their bivariate version (Canterbury approximants) [3] \, and\, as a
novel approach\, Quadratic approximants [4]\, which are very interesting\
, specially\, for the η case. Finally\, we calculate the branching ratios
for the different processes and estimate the different uncertainties\, hi
ghlighting possible future experiments that may improve our description.\n
\nReferences\n1. P. Masjuan\, Phys. Rev. D 86\, 094021 (2012).\n2. R. Escr
ibano\, P. Masjuan\, and P. Sanchez-Puertas\, Phys. Rev. D 89\, 034014\, (
2014).\n3. P. Masjuan\, and P. Sanchez-Puertas\, In preparation.\n2. S. Go
nzalez-Solis\, P. Masjuan\, and P. Sanchez-Puertas\, In preparation.\n\nht
tps://agenda.infn.it/event/7897/contributions/70661/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70661/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Single and double Dalitz decays of pi^0\, eta and eta' through rat
ional approximants
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70660@agenda.infn.it
DESCRIPTION:Speakers: Sergi González-Solís (IFAE-Autonomous University o
f Barcelona)\nI will analyze the anomalous single and double Dalitz decays
of the neutral pseudoscalar mesons\, P → l+ l− γ and P → l+ l− l
+ l− (P = π \, η\, η' \; l= e or µ)\, employing a model-independent
transition form factor (TFF) of the Pγ∗γ(∗) vertices built up\, thro
ugh the use of rational approximants\, from the current experimental data
of the space-like TFF γ∗γ → P. Predictions for the branching ratios
and the spectra will be given and compared with present experimental statu
s.\n\nReferences\n1. R. Escribano and S. Gonzalez-Solis\, in preparation.\
n2. S. Gonzalez-Solis\, P. Masjuan and P. Sanchez-Puerts in preparation.\n
\nhttps://agenda.infn.it/event/7897/contributions/70660/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70660/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pion production in nucleon-nucleon collisions near threshold: comp
lete NNLO calculation in chiral EFT
DTSTART;VALUE=DATE-TIME:20150629T154500Z
DTEND;VALUE=DATE-TIME:20150629T160000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70659@agenda.infn.it
DESCRIPTION:Speakers: Arseniy Filin (Ruhr University\, Bochum)\nStudy of p
ion production near threshold is interesting for several reasons: it tests
applicability of chiral EFT at intermediate energies\, probes nucleon-nuc
leon dynamics at relatively large transferred momenta\, and gives possibil
ity to study isospin violation in few-body processes. The neutral pion pro
duction in pp → ppπ0 channel has been known to be the most puzzling pro
cess for a long time. The data for near-threshold cross section in this ch
annel is suppressed by more than an order of magnitude compared to charged
pion-production channels. This suppression agrees with conclusions made u
sing chiral EFT\, namely that there is almost no leading order contributio
n to pp → ppπ0 and the higher order effects are expected to be importan
t for quantitative understanding of neutral pion production. We present th
e results for the full pion production operator near threshold calculated
up-to-and-including next-to-next-to-leading order (NNLO) in chiral effecti
ve field theory [2\, 3]\, which includes pions\, nucleons and delta degree
s of freedom. Our analysis of chiral loops at NNLO reveals new mechanisms
which are important\, but haven’t been considered in phenomenological st
udies so far. The obtained production operator\, being convolved with nucl
eon-nucleon wave functions derived recently based on chiral EFT [4] is use
d to compute the pion production amplitudes. First results for the observa
bles in NN → NNπ are going to be presented.\n\nReferences\n1. V. Baru\,
C. Hanhart and F. Myhrer\, Int. J. Mod. Phys. E 23\, 4\, 1430004 (2014).\
n2. A. A. Filin\, V. Baru\, E. Epelbaum\, H. Krebs\, C. Hanhart\, A. E. Ku
dryavtsev\, and F. Myhrer\, Phys. Rev. C 85\, 054001 (2012).\n3. A. A. Fil
in\, V. Baru\, E. Epelbaum\, C. Hanhart\, H. Krebs and F. Myhrer\, Phys. R
ev. C 88\, 064003 (2013).\n4. E. Epelbaum\, H. Krebs and U.-G. Meißner\,
arXiv:1412.0142 [nucl-th] (2014).\n\nhttps://agenda.infn.it/event/7897/con
tributions/70659/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70659/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Application of low-energy theorems to NN scattering at unphysical
pion masses
DTSTART;VALUE=DATE-TIME:20150629T132500Z
DTEND;VALUE=DATE-TIME:20150629T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70658@agenda.infn.it
DESCRIPTION:Speakers: Vadim Baru (Ruhr University\, Bochum)\nThe low-energ
y theorems (LET) for NN scattering are known to provide important relation
s between the coefficients in the effective-range expansion (ERE) of the a
mplitude\, which are governed by the long-range part of the potential\, se
e\, e.g.\, [1\, 2]. Therefore\, as long as the long-range physics is appro
priately included in the calculation\, these relations should yield model
independent predictions for the coefficients in the ERE\, provided some of
these coefficients are known. In particular\, using the NN scattering len
gth in the 3S1 channel as input\, the effective range and the shape parame
ters predicted in Ref. [3] appear to be in a good agreement with those ext
racted from Nijmegen PWA [4]. In this work we extend the LET to the case o
f unphysical pion masses. It is emphasized that correlations provided by L
ET can be used as nontrivial consistency checks for the lattice calculatio
ns. As an example\, we use the m_π dependence of the effective range sugg
ested in the recent lattice study [5] as input to predict the m_π depende
nce of the binding energy and the shape parameters. Further\, we discuss t
he results of chiral extrapolations calculated to NLO using the modified W
einberg formulation of chiral effective field theory.\n\nReferences\n[1] T
. D. Cohen and J. M. Hansen\, Phys. Rev. C 59\, 13 (1999)\; Phys. Rev. C 5
9\, 3049 (1999)\;\n[2] E. Epelbaum and J. Gegelia\, Eur. Phys. J. A 41\, 3
41 (2009)\n[3] E. Epelbaum and J. Gegelia\, Phys. Lett. B 716\, 338 (2012)
\n[4] J. J. de Swart\, C. P. F. Terheggen and V. G. J. Stoks\, nucl-th/950
9032.\n[5] S. R. Beane et al. [NPLQCD Collaboration]\, Phys. Rev. C 88\, n
o. 2\, 024003 (2013)\n\nhttps://agenda.infn.it/event/7897/contributions/70
658/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70658/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Causality constraint on bound states and scattering with zero-rang
e force\, or do perturbative pions deserve another chance?
DTSTART;VALUE=DATE-TIME:20150629T134000Z
DTEND;VALUE=DATE-TIME:20150629T135500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70657@agenda.infn.it
DESCRIPTION:Speakers: Vladimir Pascalutsa (Johannes Gutenberg University\,
Mainz)\nThe present treatment of the nucleon-nucleon and few-nucleon forc
es in chiral effective theory is semi-relativistic. One of the immediate d
ifficulties of this description is that\, in accordance with Wigner’s ca
usality bound\, the leading-order (zero-range) interaction yields zero eff
ective range. This leads to the necessity of “promoting” the subleadin
g three-body force to leading order\, in the pionless theory. It eventuall
y becomes the major reason for “non-perturbative pions”. I argue that
these difficulties are absent in relativistically causal theory. On a simp
le field-theoretic example [1\,2]\, I demostrate relativistic zero-range p
otential scattering surpasses Wigner’s causality bound without violating
causality [3]. The relativistic theory exhibits a K-matrix pole necessari
ly accompanying the bound-state solution. Possible implications of these r
esults for the effective-field theory of nuclear forces will be discussed\
, time permitting.\n\nReferences\n1. V. Pascalutsa and M. Vanderhaeghen\,
“Sum rules for light-by-light scattering”\, Phys. Rev. Lett. 105 (2010
) 201603 [arXiv:1008.1088 [hep-ph]].\n2. V. Pauk\, V. Pascalutsa and M. Va
nderhaeghen\, “Analytic structure of φ4 theory using light-by-light sum
rules\,” Phys. Lett. B 725 (2013) 504.\n3. V. Pascalutsa\, “Surpassin
g Wigner’s causality bound in relativistic scattering with zero-range in
teraction\,” arXiv:1402.4973 [nucl-th].\n\nhttps://agenda.infn.it/event/
7897/contributions/70657/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70657/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Welcome by Prof. Francesco Fidecaro\, director of Phys. Dept. and
Dr. Marco Grassi\, appointed new Director of INFN-Pisa
DTSTART;VALUE=DATE-TIME:20150629T071000Z
DTEND;VALUE=DATE-TIME:20150629T072000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70656@agenda.infn.it
DESCRIPTION:Speakers: Francesco Fidecaro (Pisa University)\, Marco Grassi
(INFN-Pisa)\nhttps://agenda.infn.it/event/7897/contributions/70656/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70656/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Polarisabilities of the proton and neutron from Compton scattering
DTSTART;VALUE=DATE-TIME:20150703T103000Z
DTEND;VALUE=DATE-TIME:20150703T111000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70655@agenda.infn.it
DESCRIPTION:Speakers: Judith McGovern (University of Manchester)\nWe have
recently completed a high-precision extraction of the proton spin-independ
ent polarisabilities from the world database of low-energy Compton scatter
ing experiments\, within the framework of chiral effective field theory (
χEFT) with pions\, nucleons\, and the Delta(1232) as explicit degrees of
freedom [1]. Our Baldin-sum-rule-constrained results are [2]\nα_p = 10.65
± 0.35(stat) ± 0.2(Baldin) ± 0.3(theory)\,\nβ_p = 3.15 ± 0.35(stat)
± 0.2(Baldin) ± 0.3(theory).\nThese were obtained in the heavy-baryon fo
rmulation\, but almost identical results have been obtained in a covariant
calculation [3]. With the publication this year by Myers et al. of the re
sults of the deuteron Compton scattering experiment using the Tagged-Photo
n Facility at the MAX IV Laboratory in Lund\, Sweden\, the world γ-d data
base has doubled in size\, allowing the extraction of the isoscalar polari
sabilities with unprecedented accuracy\, and combined with the proton resu
lts we obtain [4]\nα_n = 11.65 ± 1.25(stat) ± 0.2(Baldin) ± 0.8(theory
)\,\nβ_n = 3.55 ± 1.25(stat) ± 0.2(Baldin) ± 0.8(theory).\nA new gener
ation of experiments with polarised beams have been performed at the Mainz
Microtron\, with the first results published this year by Martel et al. [
5]. These experiments are sensitive to the spin polarisabilities\, and we
will discuss the predictions of χEFT for the relevant cross sections cros
s sections and asymmetries.\n\nReferences\n1. H. W. Griesshammer\, J. A. M
cGovern\, D. R. Phillips and G. Feldman\, Prog. Part. Nucl. Phys. 67 (2012
) 841 [arXiv:1203.6834 [nucl-th]].\n2. J. A. McGovern\, D. R. Phillips and
H. W. Griesshammer\, Eur. Phys. J. A 49 (2013) 12 [arXiv:1210.4104 [nucl-
th]].\n3. V. Lensky and J. A. McGovern\, Phys. Rev. C 89 (2014) 032202. [a
rXiv:1401.3320 [nucl-th]].\n4. L. S. Myers et al. COMPTON@MAX-lab Collabor
ation]\, Phys. Rev. Lett. 113 (2014) 26\, 262506 [arXiv:1409.3705 [nucl-ex
]].\n5. P. P. Martel et al. [A2 Collaboration]\, Phys. Rev. Lett. 114 (201
5) 11\, 112501 [arXiv:1408.1576 [nucl-ex]].\n\nhttps://agenda.infn.it/even
t/7897/contributions/70655/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70655/
END:VEVENT
BEGIN:VEVENT
SUMMARY:How well does the chiral expansion converge
in nuclear and neutron matter?
DTSTART;VALUE=DATE-TIME:20150630T091000Z
DTEND;VALUE=DATE-TIME:20150630T095000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70654@agenda.infn.it
DESCRIPTION:Speakers: Francesca Sammarruca (University of Idaho\, Moscow)\
nThe equations of state of nuclear and neutron matter (and\, more generall
y\, neutron-rich matter) play a fundamental role towards the understanding
of a broad spectrum of systems\, ranging from the skins of neutron-rich n
uclei to the structure of compact stars.\n\nAfter a brief introduction on
different approaches to the properties of nuclear/neutron matter\, we will
focus on error quantification in effective field theory. The various sour
ces of uncertainty and their impact in infinite matter will be explored.\n
\nWe will report on recent calculations of the nuclear and neutron matter
equations of state [1] at different orders of the chiral expansion as well
as changing resolution scale. We will discuss the significance of such pr
edictions as a foundation for future studies of convergence of the chiral
perturbation series.\n\n1. F. Sammarruca\, L. Coraggio\, J.W. Holt\, N. It
aco\, R. Machleidt\, and L.E. Marcucci\, Phys. Rev. C 91\, 054311 (2015)\n
\nhttps://agenda.infn.it/event/7897/contributions/70654/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70654/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inclusion of isospin breaking effects in lattice simulations
DTSTART;VALUE=DATE-TIME:20150701T095000Z
DTEND;VALUE=DATE-TIME:20150701T103000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70653@agenda.infn.it
DESCRIPTION:Speakers: Antonin Portelli (University of Southampton)\nIsospi
n symmetry is explicitly broken in the Standard Model by the mass and elec
tric charge of the up and down quarks. These effects represent a perturbat
ion of hadronic amplitudes at the percent level. Although these contributi
ons are small\, they play a crucial role in hadronic and nuclear physics.
Moreover\, as lattice computations are becoming increasingly precise\, it
is becoming more and more important to include these effects in numerical
simulations. We summarize here how to properly define QCD and QED on a fin
ite and discrete space-time so that isospin corrections to hadronic observ
ables can be computed ab-initio and we review the main results on the isos
pin corrections to the hadron spectrum. We mainly focus on the recent work
going beyond the electro-quenched approximation.\n\nhttps://agenda.infn.i
t/event/7897/contributions/70653/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70653/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Muon anomalous magnetic moment and hadronic vacuum polarization: R
ecent developments
DTSTART;VALUE=DATE-TIME:20150703T080500Z
DTEND;VALUE=DATE-TIME:20150703T084500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70652@agenda.infn.it
DESCRIPTION:Speakers: Simon Eidelman (Budker Institute of Nuclear Physics\
, Novosibirsk)\nWe discuss the current status of the theoretical predictio
n for the muon anomalous magnetic moment in Standard Model. Recent develop
ments in estimation of hadronic vacuum polarization are described based on
measurements of e+ e− → hadrons cross section in Novosibirsk and Beij
ing as well as those with ISR at KLOE\, BaBar and Belle. We also briefly r
eview expectations for experiment and theory in close future.\n\nhttps://a
genda.infn.it/event/7897/contributions/70652/
LOCATION:Buiding E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70652/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nuclear physics from QCD on lattice
DTSTART;VALUE=DATE-TIME:20150630T064500Z
DTEND;VALUE=DATE-TIME:20150630T072500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70651@agenda.infn.it
DESCRIPTION:Speakers: Takashi Inoue (Nihon University)\nExplaining and pre
dicting properties of nuclei starting from QCD is one of the most challeng
ing problems in physics. There are several attempts to extract mass of nuc
lei in lattice QCD simulations\, but direct extractions are limited only t
o very light nuclei\, i.e. mass number A ≤ 4\, due to computation costs
and\, more severely\, due to several fundamental difficulties. We propose
an alternative approach to study nuclei starting from QCD. We deduce mass
and structure of 4He\, 16O\, and 40 Ca nuclei from QCD. First\, we extract
two-nucleon potentials in lattice QCD numerical simulations with the rece
ntly developed HAL QCD method\, at large quark masses for the moment. Obta
ined QCD induced NN potentials posses common features of phenomenological
ones\, namely\, strong repulsion at short distance\, attraction at medium
and long distance\, and strong tensor force\, although their strength are
weaker due to the large quark masses. Accordingly\, the potentials reprodu
ce experimental two-nucleon scattering data qualitatively. Then\, we apply
the potentials to few-body technique or many-body theory to study the nuc
lei: a variational method for 4He and the Brueckner-Hartree-Fock (BHF) the
ory for 16O and 40Ca. We find that these nuclei are bound for a large quar
k mass corresponding to a pseudo-scalar meson mass of 469 MeV and a nucleo
n mass of 1161 MeV.\n\nFig. 1 (see the attached file) shows obtained groun
d state energy of 16O as a function of parameters used in our BHF calculat
ion. Fig. 2 shows obtained single particle levels of 40Ca. Total binding e
nergies\, 5 MeV for 4He\, 35 MeV for 16O\, and 113 MeV for 40Ca\, are rath
er smaller than the experimental data\, but this is primarily because of t
he unrealistic quark mass in our lattice QCD simulation. This result shows
that one can deduce properties of medium- heavy nuclei from QCD as well a
s light ones in the HAL QCD approach. This must be significant progress in
nuclear physics.\n\nReferences\n1. T. Inoue et al. [HAL QCD Collaboration
]\, Nucl. Phys. A881 (2012) 28.\n2. T. Inoue et al. [HAL QCD Collaboration
]\, Phys. Rev. Lett. 111 (2013) 11\, 112503.\n3. T. Inoue et al. [HAL QCD
Collaboration]\, Phys. Rev. C91 (2015) 1\, 011001.\n\nhttps://agenda.infn.
it/event/7897/contributions/70651/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70651/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Progress on the muon anomalous magnetic moment from lattice QCD
DTSTART;VALUE=DATE-TIME:20150703T072500Z
DTEND;VALUE=DATE-TIME:20150703T080500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70650@agenda.infn.it
DESCRIPTION:Speakers: Tom Blum (University of Connecticut\, Storrs)\nRecen
t studies of the hadronic vacuum polarization and hadronic light-by-light
scattering contributions to the muon anomalous magnetic moment (g-2) are r
eviewed. Attention is paid to systematic errors arising from finite volume
and non-zero lattice spacing\, among others. The problem of disconnected
quark loop diagrams is also discussed.\n\nhttps://agenda.infn.it/event/789
7/contributions/70650/
LOCATION:Buiding E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70650/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dispersive treatment of the hadronic light-by-light contribution t
o (g-2)_mu
DTSTART;VALUE=DATE-TIME:20150703T064500Z
DTEND;VALUE=DATE-TIME:20150703T072500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70649@agenda.infn.it
DESCRIPTION:Speakers: Gilberto Colangelo (University of Berne)\nI will des
cribe recent progress in approaching the calculation of the hadronic light
-by-light contribution to (g-2)_mu with dispersive methods. I will first d
iscuss general properties of the four-point function of the electromagneti
c current in QCD\, its Lorentz decomposition and dispersive representation
. For what concerns the pseudoscalar pole contributions\, I will give an o
verview of the determination of the pseudoscalar transition form factors.
I will then consider the pion-loop contribution and discuss the recently p
roposed Mandelstam representation thereof.\n\nhttps://agenda.infn.it/event
/7897/contributions/70649/
LOCATION:Buiding E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70649/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Compton scattering and the nucleon polarizabilities
DTSTART;VALUE=DATE-TIME:20150703T095000Z
DTEND;VALUE=DATE-TIME:20150703T103000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70648@agenda.infn.it
DESCRIPTION:Speakers: Evangeline Downie (George Washington University\, Wa
shington)\nPolarizabilities are fundamental properties of the nucleon whic
h can be accessed by measuring the differential cross section\, and singly
and doubly polarized asymmetries in real Compton scattering (RCS). Their
measurement gives rise to a better understanding of nucleon dynamics and
structure. Polarizabilities play an important role in many areas of physi
cs: from being the largest component of the theory error in the extraction
of the radius of the proton from the Lamb shift\, to influencing neutron
star physics. Despite their all-pervading nature\, and great theoretical
interest\, there is still a large uncertainty in the nucleon scalar polari
zabilities\, and the nucleon spin polarizabilities had\, until recently\,
never been individually measured [1].\n\nCompton Scattering data. In ord
er to minimize and control the model-dependence of the of the extraction\,
it is imperative to use a variety of different theory flavors and models.
It is also important to measure over as broad an energy and angular rang
e as possible in order to provide a strenuous test of the various theories
. The small-cross section RCS process can be difficult to cleanly extract
from the data\, it is therefore necessary to measure these RCS asymmetrie
s at multiple laboratories with differing beam types and detector setups.
To this end\, there are active RCS programs at MAX-IV in Lund\, and HIGS a
t TUNL in addition to MAMI. \n \nThe polarizabity measurement program rel
ies on theory to extract the polarizabilities from the real Compton Scatte
ring data. In order to minimize and control the model-dependence of the o
f the extraction\, it is imperative to use a variety of different theory f
lavors and models. It is also important to measure over as broad an energ
y and angular range as possible in order to provide a strenuous test of th
e various theories. The small-cross-section RCS process can be difficult t
o cleanly extract from the data\, it is therefore necessary to measure the
se RCS asymmetries at multiple laboratories with differing beam types and
detector setups. To this end\, there are active RCS programs at MAX-IV in
Lund\, and HIGS at TUNL in addition to MAMI.\n\nThe MAMI measurement progr
am spans spin and scalar polarizabilities [2]\, with data taken on three d
ifferent asymmetries (Sigma_{2x}\, Sigma_{2z}\, and Sigma_{3}) in the regi
on of the delta resonance in order to obtain the spin polarizabilities [3]
. These are the first measurements of doubly polarized asymmetries in real
Compton scattering. There has also been a measurement of Sigma_{3} below
pion production threshold in order to extract the proton scalar electric
and magnetic polarizabilities (alpha_{E1} and beta_{M1}\, respectively) in
dependently from each other. At HIGS\, there are planned Sigma_{2x} and S
igma_{3} measurements and the neutron measurement program is also in progr
ess. Al MAX-!V\, the final nuclear physics measurement is planned to be RC
S on the deuteron. MAMI too is moving towards neutron measurements with p
lanned RCS cross section measurements on ^{3/4}He. The theory development
necessary for the interpretation of the data is also already well underway
[4].\n\nIn these times of great change and new data\, we will provide an
overview of the current status of the experimental program across all thre
e labs and the future outlook.\n\nReferences\n1. H.W.Griesshammer\, J.A.Mc
Govern\, D.R.Phillips and G.Feldman\, Prog. Part. Nucl. Phys. 67 (2012) 84
1.\n2. E.J.Downie and H.Fonvieille\, Eur. Phys. J. ST 198 (2011) 287-306.\
n3. P.P.Martel et al.\, Phys. Rev. Lett. 114\, (2015) 112501.\n4. H.W.Grie
sshammer\, D.R.Phillips\, B.Strandberg\, in preparation.\n\nhttps://agenda
.infn.it/event/7897/contributions/70648/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70648/
END:VEVENT
BEGIN:VEVENT
SUMMARY:QED corrections to hadronic processes in lattice QCD
DTSTART;VALUE=DATE-TIME:20150702T080500Z
DTEND;VALUE=DATE-TIME:20150702T084500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70647@agenda.infn.it
DESCRIPTION:Speakers: Vittorio Lubicz (Roma3 University)\nRecently\, a met
hod has been proposed for the first time to compute electromagnetic effect
s in hadronic processes using lattice simulations. The method can be appli
ed\, for example\, to the leptonic and semileptonic decays of light or hea
vy pseudoscalar mesons. For these quantities the presence of infrared dive
rgences in intermediate stages of the calculation makes the procedure more
complicated than is the case for the hadronic spectrum\, for which lattic
e calculations already exist. In this talk\, I illustrate the method for t
he leptonic decays of a pseudoscalar meson. Its practical implementation\,
although challenging\, is within reach of the present lattice technology.
Electromagnetic and isospin breaking corrections to quark and hadron mass
es will be also briefly reviewed\, mainly relying on the analysis performe
d by the FLAG working group.\n\nReferences\n1. N. Carrasco\, V. Lubicz\, G
. Martinelli\, C. T. Sachrajda\, N. Tantalo\, C. Tarantino and M. Testa\,
arXiv:1502.00257 [hep-lat].\n2. FLAG Working Group\, S. Aoki et al.\, Eur.
Phys. J. C 74 (2014) 9\, 2890.\n\nhttps://agenda.infn.it/event/7897/contr
ibutions/70647/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70647/
END:VEVENT
BEGIN:VEVENT
SUMMARY:B_{l4} decays and the extraction of |V_ub|
DTSTART;VALUE=DATE-TIME:20150629T144000Z
DTEND;VALUE=DATE-TIME:20150629T150000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70646@agenda.infn.it
DESCRIPTION:Speakers: Xian-Wei Kang (IAS and IKP\, Forschungszentrum Jüli
ch)\nThe Cabibbo-Kobayashi-Maskawa matrix element |Vub| is not well determ
ined yet. It can be extracted from both inclusive or exclusive decays\, li
ke B → ρ(π)l¯νl. However\, the exclusive determination from B → ρ
l¯νl\, in particular\, suffers from a large model dependence. In this ta
lk\, I will elaborate our proposal [1]: extracting |Vub| from the four- bo
dy semileptonic decay B → ππl¯νl\, where the form factors for the pi
on-pion system are treated in dispersion theory. This is a model-independe
nt approach that takes into account the ππ rescattering effects\, as wel
l as the effect of the ρ meson. We demonstrate that both finite-width eff
ects of the ρ meson as well as scalar ππ contributions can be considere
d completely in this way.\n\nReferences\nX.-W. Kang\, B. Kubis\, C. Hanhar
t and U.-G. Meißner\, Phys. Rev. D 89\, 053015 (2014).\n\nhttps://agenda.
infn.it/event/7897/contributions/70646/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70646/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Combined analysis of the decays τ−→KSπ−ντ and τ−→K
−ηντ
DTSTART;VALUE=DATE-TIME:20150630T161000Z
DTEND;VALUE=DATE-TIME:20150630T163000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70645@agenda.infn.it
DESCRIPTION:Speakers: Rafel Escribano (Autonomous University of Barcelona)
\nIn a combined study of the decay spectra of τ−→KSπ−ντ and τ
−→K−ηντ decays within a dispersive representation of the required
form factors\, we illustrate how the K∗(1410) resonance parameters\, de
fined through the pole position in the complex plane\, can be extracted wi
th improved precision as compared to previous studies. While we obtain a s
ubstantial improvement in the mass\, the uncertainty in the width is only
slightly reduced\, with the findings MK∗′=1304±17MeV and ΓK∗′=17
1±62MeV. Further constraints on the width could result from updated analy
ses of the Kπ and/or Kη spectra using the full Belle-I data sample. Pros
pects for Belle-II are also discussed. As the K−π0 vector form factor e
nters the description of the decay τ−→K−ηντ\, we are in a positi
on to investigate isospin violations in its parameters like the form facto
r slopes. In this respect also making available the spectrum of the transi
tion τ−→K−π0ντ would be extremely useful\, as it would allow to
study those isospin violations with much higher precision.\n\nhttps://agen
da.infn.it/event/7897/contributions/70645/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70645/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hyperon forward spin polarizability gamma0 in baryon chiral pertur
bation theory
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70644@agenda.infn.it
DESCRIPTION:Speakers: Astrid Hiller Blin (IFIC\, University of Valencia)\n
We present the calculation of the hyperon forward spin polarizability gamm
a0 using manifestly Lorentz covariant baryon chiral perturbation theory in
cluding the intermediate contribution of the isospin-3/2 states. As at the
considered order the extraction of gamma0 is a pure prediction of chiral
perturbation theory and does not depend on renormalization schemes\, the o
btained values are a good test for this theory. Our results have a very go
od agreement with the experimental data for nucleons. Therefore we extend
our frame to hyperons to give predictions to their gamma0 values.\n\nhttps
://agenda.infn.it/event/7897/contributions/70644/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70644/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Applying Efimov physics to few nucleon systems
DTSTART;VALUE=DATE-TIME:20150629T151500Z
DTEND;VALUE=DATE-TIME:20150629T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70643@agenda.infn.it
DESCRIPTION:Speakers: Alejandro Kievsky (INFN-Pisa)\nEfimov physics has be
en intensively studied in the L=0\, spatially symmetric state of the three
-boson system. In the case of three nucleons\, the three and four-body sys
tems have a large symmetric component allowing the study of Efimov physics
. To be recalled in this context the large values of the singlet and tripl
et two-nucleon scattering lengths. In this presentation we will show resul
ts for low energy observables using simple potential models with variable
strength. In this way the dependence with the triplet and singlet scatteri
ng length values can be analyzed\, in particular at the unitary limit\, 1/
a=0. On the other hand\, at the physical values of the scattering length a
nd using a three-body force different observables can be quantitatively re
produced as the doublet and quartet n-d scattering lengths\, the low energ
y s-wave n-d phases and the binding energies of the ground and excited sta
tes of the alpha particle. The impact in the six nucleon system will be an
alyzed.\n\nhttps://agenda.infn.it/event/7897/contributions/70643/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70643/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The nucleon-nucleon interaction up to sixth order in the chiral ex
pansion
DTSTART;VALUE=DATE-TIME:20150630T124500Z
DTEND;VALUE=DATE-TIME:20150630T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70642@agenda.infn.it
DESCRIPTION:Speakers: Ruprecht Machleidt (University of Idaho\, Moscow)\nW
e have calculated the nucleon-nucleon (NN) interaction up to sixth order (
N5LO) of chiral perturbation theory [1\,2]. Previous calculations [3] exte
nded only up to N3LO (fourth order) and typically showed a surplus of attr
action\, particularly\, when the πN LECs from πN analysis were applied c
onsistently. Furthermore\, the contributions at N2LO and N3LO are both fai
rly sizeable\, thus\, raising concerns about the convergence of the chiral
expansion. We show that the N4LO contribution is repulsive and\, essentia
lly\, cancels the excessive attraction of N3LO. The N5LO contribution turn
s out to be considerably smaller than the N4LO one\, hence establishing th
e desired trend of convergence. The predictions at N5LO are in excellent a
greement with the empirical phase shifts of peripheral partial waves (cf.
Fig. 1).\n\nReferences\n1. D. R. Entem\, N. Kaiser\, R. Machleidt\, and Y.
Nosyk\, Phys. Rev. C 91\, 014002 (2015).\n2. D. R. Entem\, N. Kaiser\, R.
Machleidt\, and Y. Nosyk\, to be published.\n3. R. Machleidt and D. R. En
tem\, Phys. Reports 503\, 1 (2011).\n\nhttps://agenda.infn.it/event/7897/c
ontributions/70642/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70642/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peripheral transverse densities in the light-front formulation of
chiral dynamics
DTSTART;VALUE=DATE-TIME:20150702T132000Z
DTEND;VALUE=DATE-TIME:20150702T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70641@agenda.infn.it
DESCRIPTION:Speakers: Carlos Granados (Uppsala University)\nThe transverse
densities of charge and magnetization in the nucleon are studied at perip
heral transverse distances (~O(M_pi^-1))\, where they are dominated by chi
ral dynamics and can be calculated model-independently using ChEFT. The de
nsities are represented as overlap integrals of chiral light-front wave fu
nctions\, describing the transition of the initial nucleon to soft pion-nu
cleon (and Delta) intermediate states and back [1]. This first-quantized r
epresentation of chiral dynamics permits a simple quantum-mechanical inter
pretation and reveals new features of the transverse densities. The orbita
l motion of the peripheral pion causes a large left-right asymmetry of the
current in a transversely polarized nucleon\, which results in the approx
imate equality of the peripheral charge and magnetization densities. The s
triking effect testifies to the essentially relativistic nature of chiral
dynamics and could be observed in nucleon electromagnetic form factor meas
urements at low momentum transfer. The methodology developed here can be a
pplied to nucleon form factors of other operators\, such as the energy-mom
entum tensor.\n\nReferences\n[1] C. Granados\, C. Weiss\, arXiv:1503.02055
\, arXiv:1503.04839\n\nhttps://agenda.infn.it/event/7897/contributions/706
41/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70641/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The n3He experiment: Hadronic parity violation in cold neutron cap
ture on 3He.
DTSTART;VALUE=DATE-TIME:20150629T144500Z
DTEND;VALUE=DATE-TIME:20150629T150000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70640@agenda.infn.it
DESCRIPTION:Speakers: Michael Gericke (University of Manitoba\, Winnipeg)\
nThe n3He experiment aims to measure the parity violating asymmetry in the
direction of proton emission in the reaction vec{n}+3He-> 3H+p\, using th
e capture of polarized cold neutrons in an unpolarized gaseous 3He target.
Using effective field theory based calculations\, the size of the asymme
try is estimated to be in the range of (-9.5 --> 2.5) X 10^{-8}\, and our
goal measurement accuracy is 2 X 10^{-8}. The asymmetry is a result of th
e low energy weak interaction between nucleons and its measurement will pr
ovide a benchmark for modern effective field theory calculations. The asym
metry isolates the I = 0 components of the hadronic weak interaction. The
experiment uses a 3He multiwire ionization chamber as the combined target
and detector operated in current mode. The n3He experiment was installed
and commissioned in December 2014 on the Fundamental Neutron Physics Beaml
ine at the Spallation Neutron Source at Oak Ridge National Laboratory. The
experiment is currently taking production data. I will provide an overvi
ew of the experiment and the physics and will discuss some of the data col
lected to date.\n\nhttps://agenda.infn.it/event/7897/contributions/70640/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70640/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Low-energy constants from ALEPH hadronic tau decay data
DTSTART;VALUE=DATE-TIME:20150630T161000Z
DTEND;VALUE=DATE-TIME:20150630T163000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70639@agenda.infn.it
DESCRIPTION:Speakers: Maarten Golterman (San Francisco State University)\n
We determined the NLO chiral low-energy constant L_10\, and various combin
ations of NNLO chiral low-energy constants employing recently revised ALEP
H results for the non-strange vector (V) and axial-vector (A) hadronic tau
decay distributions and recently updated RBC/UKQCD lattice data for the n
on-strange V-A two-point function. In this talk\, we explain the ingredie
nts of this determination. Our errors are at or below the level expected
for contributions of yet higher order in the chiral expansion\, and we the
refore believe that our analysis exhausts the possibilities of what can be
meaningfully achieved in an NNLO analysis.\n\nhttps://agenda.infn.it/even
t/7897/contributions/70639/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70639/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Magnetic properties of light nuclei from lattice QC
D
DTSTART;VALUE=DATE-TIME:20150629T123000Z
DTEND;VALUE=DATE-TIME:20150629T125500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70638@agenda.infn.it
DESCRIPTION:Speakers: Martin Savage (Institute for Nuclear Theory\, Seattl
e)\nI will present the recent results of lattice QCD calculations of the i
nteractions of nucleons and light nuclei with magnetic fields. Their magne
tic moments and polarizabilities have been calculated at pion masses of 80
5 MeV and 450 MeV. Interestingly\, the magnetic moments\, when given in te
rms of natural nuclear magnetons\, are found to be consistent with the exp
erimental values. I also present first results for the cross section for n
+ p → d + γ.\n\nhttps://agenda.infn.it/event/7897/contributions/70638/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70638/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Leading logarithms for mesons and nucleons
DTSTART;VALUE=DATE-TIME:20150630T142000Z
DTEND;VALUE=DATE-TIME:20150630T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70637@agenda.infn.it
DESCRIPTION:Speakers: Johan Bijnens (Lund University)\nThe talk will give
an overview of the work done recently in calculating leading logarithms to
high order and the underlying methods used. The method used [1\,2] will b
e done and an over view of applications which have been done to very high
order in the massless case and up to seven loops in the massive case [3\,4
\,5]. The talk will concentrate mainly on the new aspects needed for the n
ucleon sector where we can also obtain subleading logarithms in some cases
. We also present some numerical results [5].\n\nReferences\n[1] Leading
Logarithms in the Massive O(N) Nonlinear Sigma Model\, Johan Bijnens\, Lis
a Carloni\, Nucl.Phys. B827 (2010) 237-255\n[2] Chiral Logarithms in the M
assless Limit Tamed\, N. Kivel\, M.V. Polyakov\, A. Vladimirov\, Phys.Rev.
Lett. 101 (2008) 262001\n[3] Leading logarithms in the anomalous sector of
two-flavour QCD\, Johan Bijnens\, Karol Kampf\, Stefan Lanz\, Nucl.Phys.
B860 (2012) 245-266\n[4] Leading logarithms in N-flavour mesonic Chiral Pe
rturbation Theory\, Johan Bijnens\, Karol Kampf\, Stefan Lanz\, Nucl.Phys.
B873 (2013) 137-164\n[5] Leading logarithms for the nucleon mass\, Johan
Bijnens\, Alexey A. Vladimirov\, Nucl.Phys. B891 (2015) 700-719\n\nhttps:/
/agenda.infn.it/event/7897/contributions/70637/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70637/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Finite volume for masses and decay constants
DTSTART;VALUE=DATE-TIME:20150629T154000Z
DTEND;VALUE=DATE-TIME:20150629T160000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70636@agenda.infn.it
DESCRIPTION:Speakers: Thomas Rössler (Lund University)\nThe talk will cov
er the recent progress in Chiral Perturbation Theory at two-loop order in
finite volume. The techniques used in the two-loop finite volume integrals
[1] will be described shortly and afterwards applications to masses and d
ecay constants both for the standard case in two and three flavours [2] an
d partially quenched for three sea quark flavours [3] will be discussed.\n
\n[1] Two-loop Sunset Integrals at Finite Volume\, Johan Bijnens\, Emil Bo
ström\, Timo A. Lähde\, JHEP 1401 (2014) 019\n[2] Finite Volume at Two-l
oops in Chiral Perturbation Theory\, Johan Bijnens\, Thomas Rössler\, JHE
P 1501 (2015) 034\n[3] Johan Bijnens\, Thomas Rössler\, work in progress\
n\nhttps://agenda.infn.it/event/7897/contributions/70636/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70636/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masses\, decay constants and electromagnetic form-factors with twi
sted boundary conditions
DTSTART;VALUE=DATE-TIME:20150629T160000Z
DTEND;VALUE=DATE-TIME:20150629T162000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70635@agenda.infn.it
DESCRIPTION:Speakers: Johan Relefors (Lund University)\nThe talk will desc
ribe the recent work at one-loop Chiral perturbation Theory with twisted b
oundary conditions [1]. We point out that due to the broken Lorentz and r
eflection symmetry a number of new terms show up in the expressions. The p
seudo-scalar octet masses\, axial-vector and pseudo-scalar decay constants
and electromagnetic form-factors will be discussed explicitly. We show ho
w the Ward identities are satisfied using the momentum dependent masses an
d the non-zero vacuum-expectation-values values for the electromagnetic (v
ector) currents. A short discussion of the needed one-loop twisted finite
volume integrals as well as the the ongoing work for the K_{l3} form fact
ors will be included [2].\n\n[1] Masses\, Decay Constants and Electromagne
tic Form-factors with Twisted Boundary Conditions\, Johan Bijnens\, Johan
Relefors\, JHEP 1405 (2014) 015\n[2] C. Bernard\, J. Bijnens\, E. Gamiz\,
J. Relefors\, work in progress\n\nhttps://agenda.infn.it/event/7897/contri
butions/70635/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70635/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Welcome
DTSTART;VALUE=DATE-TIME:20150629T072000Z
DTEND;VALUE=DATE-TIME:20150629T072500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70634@agenda.infn.it
DESCRIPTION:Speakers: Laura Elisa Marcucci ()\nhttps://agenda.infn.it/even
t/7897/contributions/70634/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70634/
END:VEVENT
BEGIN:VEVENT
SUMMARY:3rd announcement
DTSTART;VALUE=DATE-TIME:20150702T084500Z
DTEND;VALUE=DATE-TIME:20150702T084600Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70633@agenda.infn.it
DESCRIPTION:Speakers: Michele Viviani ()\nhttps://agenda.infn.it/event/789
7/contributions/70633/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70633/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Closing
DTSTART;VALUE=DATE-TIME:20150703T111000Z
DTEND;VALUE=DATE-TIME:20150703T112000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70632@agenda.infn.it
DESCRIPTION:Speakers: Michele Viviani (INFN-Pisa)\nhttps://agenda.infn.it/
event/7897/contributions/70632/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70632/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Status and prospects of the KOTO experiment
DTSTART;VALUE=DATE-TIME:20150702T134000Z
DTEND;VALUE=DATE-TIME:20150702T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70631@agenda.infn.it
DESCRIPTION:Speakers: Yu-Chen TUNG (University of Chicago)\nKOTO at J-PARC
is the dedicated experiment to probe the KL➞π0νν decay\, which is co
nsidered as a golden decay as its clean theoretical branching ratio and po
tential to test the standard model and physics beyond it. After J-PARC res
toring from the radiation accident in 2013\, KOTO has already started data
taking\, aiming to reach the standard model sensitivity of O(10^-11) i
n three years. We will present the current status and our future plan.\n\n
https://agenda.infn.it/event/7897/contributions/70631/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70631/
END:VEVENT
BEGIN:VEVENT
SUMMARY:An overview of recent nucleon spin structure measurements at Jeffe
rson Lab
DTSTART;VALUE=DATE-TIME:20150702T072500Z
DTEND;VALUE=DATE-TIME:20150702T080500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70630@agenda.infn.it
DESCRIPTION:Speakers: Kalyan Allada (Massachusetts Institute of Technology
)\nOur understanding of nucleon spin structure is still far from complete.
Experiments conducted at Jefferson Lab have made significant contribution
s to improve our knowledge of the longitudinal spin structure by measuring
polarized structure functions\, g1 and g2\, down to Q^2 = 0.02 GeV^2. The
low Q^2 data is especially useful in testing the Chiral Perturbation theo
ry (ChiPT) calculations. The spin-dependent sum rules and the spin polariz
abilities\, constructed from the moments of g1 and g2\, provide an importa
nt tool to study the longitudinal spin structure. We will present an overv
iew of the experimental program to measure these structure functions at Je
fferson Lab\, and present some recent results on the neutron polarizabilit
ies\, proton g1 at low Q^2\, and proton and neutron d2 measurements. In ad
dition to this\, we will discuss the transverse spin structure of the nucl
eon which can be accessed using chiral-odd transversity distribution (h1)\
, and show our results from measurements done on polarized 3He target in H
all A.\n\nhttps://agenda.infn.it/event/7897/contributions/70630/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70630/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The pion polarisability and more measurements on chiral dynamics a
t COMPASS
DTSTART;VALUE=DATE-TIME:20150701T064500Z
DTEND;VALUE=DATE-TIME:20150701T072500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70629@agenda.infn.it
DESCRIPTION:Speakers: Jan Friedrich (Physik-Department E18)\nCOMPASS has r
ecently completed the analysis of pion Compton scattering measured via the
Primakoff effect. From the first available data set\, the pion polarisabi
lity is determined with unprecedented precision. It is in agreement with t
he expectation from chiral perturbation theory\, and in tension with the p
revious dedicated measurements that suggested a value about twice as large
. The multi-purpose setup of COMPASS allowed\, at the same time\, the reco
rding of pion-photon reactions that contain more pions in the final state.
Their link to chiral dynamics will be discussed as well. Meanwhile a larg
e follow-up data set has been taken\, and is under analysis. The prospects
for the gain in precision and for an extended analysis will be given.\n\n
https://agenda.infn.it/event/7897/contributions/70629/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70629/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pion photo- and electro-production and the chiral MAID interface
DTSTART;VALUE=DATE-TIME:20150701T080500Z
DTEND;VALUE=DATE-TIME:20150701T084500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70628@agenda.infn.it
DESCRIPTION:Speakers: Stefan Scherer (Johannes Gutenberg University\, Main
z)\nWe discuss the extended on-mass-shell scheme for manifestly Lorentz-in
variant baryon chiral perturbation theory. We present a calculation of pio
n photo- and electro-production up to and including order q^4. The low-ene
rgy constants have been fixed by fitting experimental data in all availabl
e reaction channels. Our results can be accessed via a web interface\, the
so-called chiral MAID (http://www.kph.uni-mainz.de/MAID/chiralmaid\, see
the attached Figure). We explain how our program works and how it can be u
sed for further analysis.\n\nhttps://agenda.infn.it/event/7897/contributio
ns/70628/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70628/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Photopion physics at MAMI
DTSTART;VALUE=DATE-TIME:20150629T091000Z
DTEND;VALUE=DATE-TIME:20150629T095000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70627@agenda.infn.it
DESCRIPTION:Speakers: David Hornidge (Mount Allison University)\nRecent me
asurements and future plans for photopion experiments with the CB-TAPS det
ector system in the A2 hall at the Mainzer Microtron will be presented. F
irst\, a measurement with linearly polarized photons and an unpolarized li
quid-hydrogen target will be discussed. The beam asymmetry along with diff
erential cross sections provide the most stringent test to date of the pre
dictions of Chiral Perturbation Theory and its energy region of convergenc
e [1]. Second\, a more recent measurement was performed using both circul
arly polarized photons and a transversely polarized butanol frozen-spin ta
rget to extract the polarization-dependent differential cross section asso
ciated with the target asymmetry [2]. Results from both measurements have
been used for a model independent determination of S- and P-wave multipol
es in the pi^0 threshold region\, which includes for the first time a dire
ct determination of the imaginary part of the E_{0^+} multipole. Finally\,
plans for a novel pi^0 photoproduction measurement on 3He to obtain the e
lusive E_{0^+} multipole for the neutron channel will be introduced.\n\nRe
ferences\n1. D. Hornidge et al.\, Phys. Rev. Lett. 111\, 062004 (2013). \n
2. S. Schumann et al.\, in preparation.\n\nhttps://agenda.infn.it/event/78
97/contributions/70627/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70627/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Clustering in nuclei from ab initio nuclear lattice
simulations
DTSTART;VALUE=DATE-TIME:20150702T123000Z
DTEND;VALUE=DATE-TIME:20150702T125500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70626@agenda.infn.it
DESCRIPTION:Speakers: Ulf-G. Meissner (HISKP\, University of Bonn)\nIn thi
s talk\, I discuss the emergence of clustering in ab initio nuclear lattic
e simulations. The spectrum and the structure of the 12C and 16O nuclei ar
e displayed. I also consider some issues related to the breaking of rotati
onal symmetry in alpha cluster-models and show how these lattice artifacts
can be tamed.\n\nhttps://agenda.infn.it/event/7897/contributions/70626/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70626/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Excited-state contamination in nucleon correlators from chiral per
turbation theory
DTSTART;VALUE=DATE-TIME:20150630T145000Z
DTEND;VALUE=DATE-TIME:20150630T151000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70625@agenda.infn.it
DESCRIPTION:Speakers: Brian Tiburzi (City College of New York)\nTechniques
to compute hadron properties from lattice QCD rely upon the limit of long
time separation. For baryons\, the signal-to-noise problem often restrict
s one to time separations that are not ideally long\, and for which coupli
ngs to excited states can obstruct the isolation of ground-state baryon p
roperties. We consider excited-state contamination in nucleon two- and thr
ee-point functions. Using chiral perturbation theory\, we determine coupli
ngs to pion-nucleon and pion-delta excited states. In two-point functions\
, these contributions are small\, in accordance with general properties of
the spectral density on a torus. For the axial-current correlation functi
on in the nucleon\, the sign of excited-state contributions suggests overe
stimation of the nucleon axial charge. Thus contamination from pion-nucleo
n excited states will not likely explain the trend in lattice QCD data.\n\
nhttps://agenda.infn.it/event/7897/contributions/70625/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70625/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scaling of tetramer properties close to the unitary limit
DTSTART;VALUE=DATE-TIME:20150629T153000Z
DTEND;VALUE=DATE-TIME:20150629T154500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70624@agenda.infn.it
DESCRIPTION:Speakers: Tobias Frederico (Instituto Tecnologico de Aeronauti
ca\, Sao Jose dos Campos)\nThe universal properties of weakly bound tetr
amers close to the unitary limit are obtained by solving Faddeev-Yakubov
sky (FY) equations for identical bosons with a zero-range interaction. The
solution of these equations demand beside a short-range three-body scale
another one for the four-boson system. We explore the correlation between
trimer and tetramer energies are shown to be universal\, and exhibits th
e effect of the new scale\, which is conveniently represented by a scaling
function depending only on dimensionless quantities. Furthermore\, the ef
fective range changes the scaling functions in a way distinct from variat
ions of the three- and four-body short range scales. The universal scaling
functions for trimer and tetramers are sensitive to the effective range\,
and in particular\, the correlation between the positions of the four-a
tom recombination peaks. We show that the shift in the position of the t
etramer resonance peaks for cesium atoms\, coming from the finite effectiv
e range\, are consistent with the existing experimental data for these b
road Feshbach resonances.\n\nhttps://agenda.infn.it/event/7897/contributio
ns/70624/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70624/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ab initio alpha-alpha scattering
DTSTART;VALUE=DATE-TIME:20150702T132500Z
DTEND;VALUE=DATE-TIME:20150702T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70623@agenda.infn.it
DESCRIPTION:Speakers: Serdar Elhatisari (University of Bonn)\nWe present
ab initio lattice calculations of alpha-alpha clusters scattering at next-
to-next-to-leading order in chiral effective field theory using the adiaba
tic projection method. The adiabatic projection method is a general framew
ork for scattering and reactions on the lattice which uses a set of initia
l cluster states and Euclidean time projection to give a systematically im
provable description of the low-lying scattering cluster states. By imposi
ng spherical wall boundary conditions\, we extract scattering phase shifts
directly from asymptotic cluster wave functions with less sensitivity to
small stochastic and systematic errors than using finite-volume energy me
thods. We present lattice results for the alpha-alpha S-wave and D-wave sc
attering phase shifts at next-to-next-to-leading order in chiral effective
field theory and compare with experimental data\n\nhttps://agenda.infn.it
/event/7897/contributions/70623/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70623/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Precise calculations of the deuteron quadrupole moment
DTSTART;VALUE=DATE-TIME:20150702T142000Z
DTEND;VALUE=DATE-TIME:20150702T143500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70622@agenda.infn.it
DESCRIPTION:Speakers: Franz Gross (Jefferson Lab)\nUntil recently\, precis
ion calculations of the deuteron quadrupole moment\, Qd\, have consistentl
y under-predicted its value by several percent\, leaving the calculation o
f this quantity an "unresolved problem" in few body physics. I will repor
t on two recent calculations that predict Qd to better than 1%. One of the
se uses chiral effective field theory and the other uses the covariant spe
ctator theory\, and comparing these very different approaches gives intere
sting insights into both of them.\n\nhttps://agenda.infn.it/event/7897/con
tributions/70622/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70622/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Resonances in coupled-channel scattering from lattice QCD
DTSTART;VALUE=DATE-TIME:20150629T125500Z
DTEND;VALUE=DATE-TIME:20150629T131000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70621@agenda.infn.it
DESCRIPTION:Speakers: David Wilson (Old Dominion University\, Norfolk)\nRe
cently it has become possible to obtain coupled-channel scattering amplitu
des using lattice QCD. Using a large basis of operators we are able to obt
ain a reliable finite volume spectrum describing the coupled pi-K\, eta-K
system. Utilizing the finite volume formalism proposed by Luescher and ext
ended by several others\, we are able to describe the spectra from each la
ttice symmetry group and this enables constraints to be derived for S\, P
and D-wave scattering. We find resonant scattering amplitudes and investig
ate their structure in the complex plane\, finding poles that display a pa
ttern similar to the physical K^*(892)\, K_0^*(1430) and K_2^*(1435) reson
ances.\n\nhttps://agenda.infn.it/event/7897/contributions/70621/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70621/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Precision measurement of the neutral pion radiative decay width at
Jefferson Lab
DTSTART;VALUE=DATE-TIME:20150702T155000Z
DTEND;VALUE=DATE-TIME:20150702T161000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70620@agenda.infn.it
DESCRIPTION:Speakers: Ashot Gasparian (North Carolina A&T State University
\, Greensboro)\nThe neutral pion is the lightest strongly interacting part
icle in Nature. Therefore\, the properties of $\\pi^0$ decay are especial
ly sensitive to the underlying fundamental symmetries of quantum chromodyn
amics (QCD). In particular\, the pi^0 -> gamma gamma decay width is primar
ily defined by the spontaneous chiral symmetry breaking effect (chiral an
omaly) in QCD. Theoretical activities in this domain over the past severa
l years have resulted in a high precision (1% level) prediction for the pi
^0 -> gamma gamma decay width. The PrimEx collaboration at Jefferson Lab h
as developed and performed two new experiments to measure the pi^0 -> gam
ma gamma decay width with high precision using the Primakoff effect. The p
ublished result from the first experiment (PrimEx-I)\, Gamma(pi^0 -> gamma
gamma) = 7.82+- 0.14 (stat) +- 0.17 (syst) eV\, is a factor of 2.1 more p
recise than the currently accepted value\, and it is in agreement with the
chiral anomaly prediction. The second experiment (PrimEx-II) was performe
d in 2010 with a goal of 1.4% total uncertainty to address the next-to-le
ading-order chiral perturbation theory calculations. The preliminary resul
ts from the PrimEx-II experiment will be presented in this talk.\n\nhttps:
//agenda.infn.it/event/7897/contributions/70620/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70620/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Status of the OLYMPUS Experiment
DTSTART;VALUE=DATE-TIME:20150629T130000Z
DTEND;VALUE=DATE-TIME:20150629T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70619@agenda.infn.it
DESCRIPTION:Speakers: Ricardo Alarcon (Arizona State University\, Tempe)\n
The OLYMPUS experiment will determine the multiple-photon exchange contrib
ution to elastic lepton-proton scattering\, the most likely candidate to r
esolve the discrepancy between measurements of the proton electric to magn
etic form factor ratio\, determined using the Rosenbluth separation techni
que and polarization transfer methods. To this end\, the experiment measur
ed the cross section ratio of positron-proton to electron-proton elastic s
cattering. Data taking took place during 2012 on the DORIS storage ring at
the DESY Laboratory in Hamburg\, Germany. Electron and positron beams of
2.01 GeV energy were incident on an unpolarized hydrogen target and the e
lastic scattering cross sections were measured for both beams using a larg
e acceptance spectrometer. This talk will cover the motivation\, experimen
t\, and current status of the analysis.\n\nhttps://agenda.infn.it/event/78
97/contributions/70619/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70619/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Improved description of the nucleon polarizabilities with relativi
stic chiral effective field theory
DTSTART;VALUE=DATE-TIME:20150629T151000Z
DTEND;VALUE=DATE-TIME:20150629T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70618@agenda.infn.it
DESCRIPTION:Speakers: Jose Manuel Alarcon (University of Bonn)\nThe electr
omagnetic structure of the nucleon has an increasing interest for experime
ntal searches of physics beyond the standard model in the precision fronti
er. The reason is that\, due to the remarkable accuracy of the experimenta
l measurements\, it is crucial to have a good understanding over all possi
ble contributions. The polarizabilities give the information about the two
photon exchange contributions stemming from the internal electromagnetic
structure of the nucleon. This is specially important for the so-called "P
roton Radius Puzzle". In this talk I will show how in a recent calculation
in the relativistic formulation of chiral effective field theory with the
Delta degrees of freedom\, we could achieve a prediction of the low Q^2 b
ehaviour of the scalar and spin polarizabilities that is in good agreement
with the MAID model and experimental data.\n\nFinally I will show the imp
act of this improved theoretical approach to the estimation of the order a
lpha_{em}^5 polarizability correction to the Lamb shift.\n\nhttps://agenda
.infn.it/event/7897/contributions/70618/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70618/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Experimental tests of nuclear interaction models in few-nucleon sy
stems
DTSTART;VALUE=DATE-TIME:20150630T134500Z
DTEND;VALUE=DATE-TIME:20150630T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70617@agenda.infn.it
DESCRIPTION:Speakers: Elzbieta Stephan (University of Silesia\, Katowice)\
nSystems of three nucleons can serve as a validation tool for the modern a
pproaches to describe nuclear interaction. At the first stage the investig
ations were mainly focused on elastic nucleon-deuteron scattering\, slowly
extending to systematic measurements of the deuteron breakup reaction [1\
,2\,3]. Intermediate energies\, below the threshold for pion production\,
deserve special attention: it is the region where comparison with exact th
eoretical calculations is possible\, while the sensitivity to various aspe
cts of interaction\, like subtle effects of the dynamics beyond the pairwi
se nucleon-nucleon force\, Coulomb interaction between protons\, or relati
vistic effects\, is significant. In addition to differential cross section
\, the observables related to nuclear polarization are studied\, like vect
or and tensor analyzing powers\, spin-correlation coefficients or polariza
tion transfer coefficients. All these effects vary with energy and appear
with different strength in certain observables and phase space regions\, w
hat calls for systematic investigations of a possibly rich set of observab
les determined in a wide range of energies. Recently\, the data base for t
he reaction of deuteron breakup in collision with proton has been signific
antly enriched in the domain of medium energies. High precision experiment
al data for cross section\, vector (proton) analyzing power and vector and
tensor (deuteron) analyzing powers were collected with detection systems
covering large part of the phase space of the 1H(d\,pp)n and 2H(p\,pp)n re
actions. Usage of the multidetector systems with significant solid angle c
overage provides not only very rich data sets but also good opportunities
for controlling consistency of the results. The experimental results are c
ompared with the theoretical predictions\, in which the full dynamics of t
he three-nucleon (3N) system is obtained in different ways: Realistic nucl
eon-nucleon (NN) potentials are combined with model 3N forces or with an e
ffective 3N interaction resulting from the explicit treatment of the ∆-i
sobar excitation. Alternatively\, the chiral perturbation theory approach
is used: At the next-to-next-to-leading order with all relevant NN and 3N
contributions taken into account\, while at the next order (N3LO) without
taking into account the corresponding 3NF contributions. The next step in
complication of the system are studies of reactions involving 4 nucleons -
more sensitive\, as expected\, to subtle dynamics beyond the pairwise int
eraction. A survey of recent and planned experiments in the 3- and 4-nucle
on systems will be given.\n\nReferences\n1. K. Sagara\, Few Body Syst. 48\
, 59 (2010).\n2. N. Kalantar-Nayestanaki\, E. Epelbaum\, J.G. Meschendorp
and A. Nogga\, Rep. Prog. Phys. 75\, 016301 (2012).\n3. St. Kistryn\, E. S
tephan\, J. Phys. G: Nucl. Part. Phys. 40\, 063101 (2013).\n\nhttps://agen
da.infn.it/event/7897/contributions/70617/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70617/
END:VEVENT
BEGIN:VEVENT
SUMMARY:From OPE to chiral perturbation theory in holographic QCD
DTSTART;VALUE=DATE-TIME:20150630T145000Z
DTEND;VALUE=DATE-TIME:20150630T151000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70616@agenda.infn.it
DESCRIPTION:Speakers: David Greynat (INFN-Naples)\nWe will show how it is
possible to implement a chiral symmetry breaking mechanism in soft-wall mo
del of holographic QCD. We show also that it is possible to reproduce the
exact Operator Product Expansion and the Regge spectra of the vector-vecto
r and axial-axial correlators in the Large Nc limit. This method provides
a nice way to perform the analytic continuation of the OPE and to predict
the chiral constants: F_pi and L_{10}.\n\nhttps://agenda.infn.it/event/789
7/contributions/70616/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70616/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Exploratory lattice QCD study of the rare kaon deca
y K+ -> pi+ nu nu-bar
DTSTART;VALUE=DATE-TIME:20150702T142000Z
DTEND;VALUE=DATE-TIME:20150702T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70615@agenda.infn.it
DESCRIPTION:Speakers: Xu Feng (Columbia University\, New York)\nThe rare k
aon decays\, K → πν¯ν\, have attracted increasing interest during th
e past few\ndecades. As ﬂavor changing neutral current processes\, these
decays are highly suppressed in the standard model and thus provide ideal
probes for the observation of new physics effects. As second-order weak i
nteractions\, the ultra-rare decays K → πν¯ν represent a signiﬁcan
t challenge in experiments. After 40 years search\, only 7 K+ → π+ ν¯
ν events have been collected in BNL E787 and E949 by 2008 [1]. A new gene
ration of experiment\, NA62 in CERN [2]\, aims at an observation of O(100)
events and a 10%-precision measurement of the branching ratio in two year
s. The standard model predictions of K → πν¯ν branching ratios are d
ominated by short-distance contributions. The long-distance contributions
below the energy scale of the charm quark mass are safely neglected in KL
→ π0 ν¯ν and are expected to be small in K+ → π+ ν¯ν. Although
small\, the long-distance contributions estimated from a phenomenological
ansatz involving both chiral perturbation theory and operator production
expansion enhance the branching ratio by 6% [3]. Recognizing that the stan
dard model predictions will soon be confronted with new experiment results
\, a lattice QCD calculation of the long-distance contribution to K+ →
π+ ν¯ν is important. In this talk I will present an exploratory calcul
ation of the long-distance contributions to the K+ → π+ ν¯ν decay am
plitude from ﬁrst principles using lattice QCD.\n\nReferences\n1. A. Art
amonovet al. (E949 Collaboration)\, Phys. Rev. Lett. 79\, 2204 (1997).\n2.
M. Moulson (NA62 Collaboration)\, (2013)\, arXiv:1310.7816.\n3. G. Isidor
i\, F. Mescia\, and C. Smith\, Nucl. Phys. B 718\, 319 (2005).\n\nhttps://
agenda.infn.it/event/7897/contributions/70615/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70615/
END:VEVENT
BEGIN:VEVENT
SUMMARY:New results for Compton scattering on deuterium: A better determin
ation of the neutron electromagnetic polarizabilities
DTSTART;VALUE=DATE-TIME:20150629T145000Z
DTEND;VALUE=DATE-TIME:20150629T151000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70614@agenda.infn.it
DESCRIPTION:Speakers: Gerald Feldman (George Washington University\, Washi
ngton)\nThe electric and magnetic polarizabilities of the proton are now r
elatively well known\, owing to Compton scattering measurements on hydroge
n targets over the past 20 years [1]. However\, in the case of the neutron
\, these structure constants are still quite uncertain\, due to the fact t
hat there are no free neutron targets and that quasi-free Compton scatteri
ng on a neutron in a nucleus has a significantly reduced cross section com
pared to that of a proton because the neutron is uncharged. These issues c
an be addressed by performing elastic Compton scattering on deuterium –
in this case\, the scattering cross section is higher\, but the contributi
ons from the proton and meson-exchange effects need to be taken into accou
nt in order to extract meaningful information about the neutron. To invest
igate this question\, a multi-institutional collaboration has been conduct
ing a program of elastic Compton scattering experiments on deuterium at th
e MAX IV Laboratory in Lund\, Sweden using tagged photons in the energy ra
nge E_γ = 65-115 MeV. We have assembled at one laboratory\, for the first
time\, three of the world’s largest NaI detectors – CATS (from Mainz)
\, BUNI (from Boston University)\, and DIANA (from the University of Kentu
cky) – each having better than ∆E/E ∼ 2% photon energy resolution. W
e have measured elastic Compton scattering cross sections at laboratory an
gles of θ_γ = 60\, 90\, 120\, and 150 deg over this energy range in 8 Me
V steps. This effectively doubles the world’s set of elastic Compton sca
ttering data from deuterium and provides valuable input for chiral effecti
ve field theory (χEFT) calculations [2]. The absolute normalization of th
e current data was rigorously checked via separate measurements of elastic
Compton scattering on carbon [3]\, which can be compared with precise val
ues in the literature. These new deuterium data overlap previous measureme
nts and extend them by 20 MeV to higher energies where the sensitivity of
the cross section to the polarizabilities is enhanced. Based on χEFT fits
to the expanded world data set\, new values for the neutron electric and
magnetic polarizabilities have been obtained with greater accuracy than pr
eviously achieved\, decreasing the statistical error by more than 30% [4].
\n\nReferences\n1. J.A. McGovern\, D.R. Phillips and H.W. Grießhammer\, E
ur. Phys. J. A 49\, 12 (2013).\n2. H.W. Grießhammer\, J.A. McGovern\, D.R
. Phillips and G. Feldman\, Prog. Part. Nucl. Phys. 67\, 841 (2012).\n3. L
.S. Myers et al.\, Phys. Rev. C 89\, 035202 (2014).\n4. L.S. Myers et al.\
, Phys. Rev. Lett. 113\, 262506 (2014).\n\nhttps://agenda.infn.it/event/78
97/contributions/70614/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70614/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Subtractive renormalization and scaling in low-energy few-body phy
sics
DTSTART;VALUE=DATE-TIME:20150702T143500Z
DTEND;VALUE=DATE-TIME:20150702T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70613@agenda.infn.it
DESCRIPTION:Speakers: Lauro Tomio (Federal University of ABC\, Sao Paolo)\
nRenormalized fixed-point Hamiltonians are formulated for systems describe
d by interactions that originally contain point-like singularities (as the
Dirac-delta and/or its derivatives). They express the renormalization gro
up invariance of quantum mechanics. The approach has been applied in the
study low-energy scattering observables\, such as the nucleon-nucleon inte
raction with one pion exchange potentials\, as well as bound-state systems
. In case of low-energy bound-state systems\, this subtractive procedure w
as found convenient to introduce the scales in formalisms with zero-range
interactions\, when renormalizing the theory. Of particular interest in re
cent years has been the studies of neutron-rich light nuclei\, with two-ne
utron halos and a core\, dominated by s-wave short-range two-body interact
ions. In this case\, the observables are expressed by universal scaling la
ws obtained in the limit of a renormalized zero-range force\, expected to
be model independent for large halos. The corresponding scaling functions
are determined by the neutron-neutron and neutron-core low-energy informat
ion\, such as scattering lengths and short-range parameters. By using rec
ent experimental data\, which constrain the two-neutron separation energy\
, we study the core momentum distribution for large halo nuclei\, like Lit
hium-11\, Carbon-20 and Carbon-22.\n\nhttps://agenda.infn.it/event/7897/co
ntributions/70613/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70613/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nuclear matter calculations with chiral interactions
DTSTART;VALUE=DATE-TIME:20150630T154500Z
DTEND;VALUE=DATE-TIME:20150630T160000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70612@agenda.infn.it
DESCRIPTION:Speakers: Domenico Logoteta (INFN-Pisa)\nWe calculate the ener
gy per particle of symmetric nuclear matter and pure neutron matter using
the many-body Brueckner-Hartree-Fock (BHF) approach and employing the Chir
al Next-to-next-to-next-to leading order (N3LO) nucleon-nucleon (NN) poten
tial supplemented with various parametrizations of the Chiral Next-to-next
-to leading order (N2LO) three-nucleon force. Such combination is able to
reproduce several observables of the physics of light nuclei for suitable
choices of the three-nucleon force parameters. We find that some of these
parametrizations\, provide also resonable values for the observables of nu
clear matter at the saturation point.\n\nhttps://agenda.infn.it/event/7897
/contributions/70612/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70612/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Precise dispersive determination of pion-nucleon sc
attering and the sigma term
DTSTART;VALUE=DATE-TIME:20150630T123000Z
DTEND;VALUE=DATE-TIME:20150630T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70611@agenda.infn.it
DESCRIPTION:Speakers: Jacobo Ruiz de Elvira (HISKP\, University of Bonn)\n
Starting from hyperbolic dispersion relations for the invariant amplitudes
of πN scattering together with crossing symmetry and unitarity\, we deri
ve and solve a closed system of integral equations for the partial waves o
f both s-channel (πN → πN) and t-channel (ππ →NN) reactions\, call
ed Roy-Steiner equations. Special attention is given to the possible sourc
es of uncertainties and to the obtained σpiN term value.\n\nhttps://agend
a.infn.it/event/7897/contributions/70611/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70611/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Form factor in VPgamma* transitions and study of th
e eta-->pi+pi-pi0 Dalitz plot at KLOE
DTSTART;VALUE=DATE-TIME:20150630T142000Z
DTEND;VALUE=DATE-TIME:20150630T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70610@agenda.infn.it
DESCRIPTION:Speakers: Simona Giovannella (INFN-LNF)\nThe KLOE experiment h
as collected 2.5 fb-1 at the peak of the phi resonance at the e+e- collide
r DAPHNE in Frascati.\n\nThe V-->Pgamma Dalitz decays\, associated to inte
rnal conversion of the photon into a lepton pair\, are not well described
by the Vector Meson Dominance (VMD) models\, as in the case of the process
omega --> pi0 mu+ mu-\, measured by the NA60 collaboration. The only exis
ting data on phi --> eta e+ e- come from the SND experiment\, which has me
asured the Mee invariant mass distribution on the basis of 213 events. At
KLOE\, a detailed study of this decay has been performed using eta-->pi0pi
0pi0 final state. We obtain the measurement of the branching fraction for
the process phi --> eta e+ e-\, with an accuracy improved by a factor of f
ive with respect to the previous most precise measurement\, and the transi
tion form factor\, which is in agreement with VMD expectations. We have al
so studied the decay phi --> pi0 e+ e-\, where no data are available on tr
ansition form factor. Dedicated analysis cuts strongly reduce the main bac
kground component of Bhabha events to ~20%\, leading to ~4000 signal event
s in the whole KLOE data set.\n\nWe have also obtained a new\, precise res
ults on the isospin-violating decay eta-->pi+pi-pi0\, sensitive to the li
ght-quark mass ratio. This study\, overcoming in precision previous resul
ts published by KLOE in 2008\, was suggested by the theoretical work: Leu
twyler\, Mod.Phys.Lett. A28 (2013) 1360014\, aiming to a better determinat
ion of the light-quark mass ratio through the dispersive analysis of the e
ta--> 3 pi decay. The new analysis\, performed with an independent and lar
ger data set (1.7 fb-1) and a new analysis scheme and improved Monte Carlo
simulation\, determines with very good accuracy the parameters of the dec
ay matrix element.\n\nhttps://agenda.infn.it/event/7897/contributions/7061
0/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70610/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Glueball decay in the Witten-Sakai-Sugimoto model
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70609@agenda.infn.it
DESCRIPTION:Speakers: Frederic Brünner (Vienna University of Technology)\
nI present new results on glueball decay rates in the Sakai-Sugimoto model
\, a holographic top-down approach for QCD with chiral quarks based on a p
robe-brane construction within Witten’s holographic model of nonsupersym
metric Yang-Mills theory. We calculated [1] rates for decays into two pion
s\, two vector mesons and four pions\, using a range of the ’t Hooft cou
pling which closely reproduces the decay rate of ρ and ω mesons and lead
s to a value for the gluon condensate consistent with QCD sum rules. We co
ncluded that the holographic mode corresponding to the lowest excitation o
f a dilatonic scalar provides a narrow glueball state in the right mass ra
nge for an identiﬁcation with f0(1500) or f0(1710)\, while the results a
ctually favour the latter as a glueball candidate. This conclusion receive
s further support from our latest work [2] on implementing ﬁnite masses
for pseudoscalar mesons by extrapolating from the calculable vertex of glu
eball ﬁelds and the η meson\, which is a consequence of the Witten-Vene
ziano mechanism. In line with the mechanism of chiral suppression [3]\, we
found a considerable enhancement of the decay of scalar glueballs into ka
ons and the η meson\, in close agreement with experimental data on f0(171
0).\n\nReferences\n1. F. Bruenner\, D. Parganlija and A. Rebhan\, Glueball
Decay Rates in the Witten-Sakai-Sugimoto Model\, arXiv:1501.07906.\n2. F.
Bruenner and A. Rebhan\, Nonchiral enhancement of scalar glueball decay i
n the Witten-Sakai-Sugimoto model \, arXiv:1504.05815.\n3. M. Chanowitz\,
Phys. Rev. Lett. 95\, 172001 (2005).\n\nhttps://agenda.infn.it/event/7897/
contributions/70609/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70609/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eta - eta' mixing in Large-Nc ChPT: discussion\, phenomenology\, a
nd prospects
DTSTART;VALUE=DATE-TIME:20150630T134000Z
DTEND;VALUE=DATE-TIME:20150630T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70608@agenda.infn.it
DESCRIPTION:Speakers: Pere Masjuan (Johannes Gutenberg University\, Mainz)
\nA detailed and systematic study of the η − η mixing in Large-Nc ChPT
will be presented [1]\, with special emphasis on the role of the next-to-
next-to-leading order contributions in the combined p^2 and N_c expansion.
At such order\, loop corrections as well as OZI-violating pieces are rele
vant for an appropriate and stable numerical result for the mixing angle.
Pseudoscalar masses as well as pseudoscalar decay constants within this fr
amework will be also presented. Comparison with recent phenomenological ap
proaches [2] together with the impact of the mixing in η'→ γγ and η'
→ ππγ decays will also be discussed.\n\nReferences\n1. P. Bickert\, P
. Masjuan\, and S. Scherer\, in preparation.\n2. R. Escribano\, P. Masjuan
\, and P. Sanchez-Puertas\, Phys. Rev. D 89 (2014) 3\, 034014 [arXiv:1307:
2061 [hep-[h]].\n\nhttps://agenda.infn.it/event/7897/contributions/70608/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70608/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral symmetry breaking and monopoles
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70607@agenda.infn.it
DESCRIPTION:Speakers: Masayasu Hasegawa (Joint Institute for Nuclear Resea
rch\, Moscow)\nIn previous works we have shown the relation between chiral
symmetry breaking\, instantons\, and monopoles by adding the monopoles to
quenched SU(3) conﬁgurations [1\,2]. We found that (i) one pair of mono
poles makes one instanton. (ii) the monopole pair induces chiral symmetry
breaking. This was done by measuring the chiral condensate computed from t
he eigenvalues and eigenvectors of the Overlap Dirac operator. In this stu
dy\, we compare the low-lying (improved) eigenvalues λi of the Overlap op
erator with the prediction of the random matrix theory [3\, 4]. First\, we
perform a scale-independent test using the low-lying eigenvalues as in Re
f. [5]. Our results are consistent with their results and the prediction o
f the random matrix theory (RMT). Next\, we add one pair of monopoles with
charges mc varying from zero to four\, to the SU(3) quenched conﬁgurati
ons\, and compare the low-lying eigenvalues with the prediction of the ran
dom matrix theory. We ﬁnd that the results of the scale-independent test
s are consistent with the prediction of the random matrix theory as shown
in Fig. 1 (λj \n\nhttps://agenda.infn.it/event/7897/contributions/70607/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70607/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Odd moments of nucleon charge and magnetization distribution in Ch
PT
DTSTART;VALUE=DATE-TIME:20150629T134000Z
DTEND;VALUE=DATE-TIME:20150629T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70606@agenda.infn.it
DESCRIPTION:Speakers: Nadiia Krupina (Johannes Gutenberg University\, Main
z)\nWe consider the predictions of Chiral Perturbation Theory (ChPT) for t
he third Zemach moment and Zemach radius and confront them with empirical
values. We look at implications of these results for the Lamb shift and hy
perfine structure of (muonic) hydrogen.\n\nhttps://agenda.infn.it/event/78
97/contributions/70606/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70606/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Narrow S-wave resonance in pion-baryon system
DTSTART;VALUE=DATE-TIME:20150630T155000Z
DTEND;VALUE=DATE-TIME:20150630T161000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70605@agenda.infn.it
DESCRIPTION:Speakers: Bingwei Long (Sichuan University\, Chengdu)\nAs the
pion mass approaches a critical value m_pi^star\, an S-wave baryon resonan
ce can cross pion-baryon threshold\, thus driving the scattering length to
diverge. Charmed baryon resonance Lambda_c^+(2595) appears to be a realiz
ation of such a system. I explore the consequences of chiral symmetry for
m_pi near m_pi^star\, which are all centered around the finding that if m_
pi^star is not too large\, the effective range of such a system is unexpec
tedly large\, proportional to 4pi f_pi^2/m_pi^3.\n\nhttps://agenda.infn.it
/event/7897/contributions/70605/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70605/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of two and three meson tau lepton decay modes with Monte Ca
rlo generator TAUOLA
DTSTART;VALUE=DATE-TIME:20150630T155000Z
DTEND;VALUE=DATE-TIME:20150630T161000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70604@agenda.infn.it
DESCRIPTION:Speakers: Olga Shekhovtsova (IFJ PAN\, Krakow)\nTAUOLA is a Mo
nte Carlo generator dedicated to generating tau-lepton decays and it is us
ed in the analysis of experimental data both at B-factories and LHC. TAUO
LA is a long term project that started in the 90's and has been under deve
lopment up to now. In the last years substantial progress for the simulati
on of the process: tau-> 3pions nu_tau was achieved. It is related with a
new parametrization of the corresponding hadronic current based on the Res
onance Chiral Lagrangian (RChL) and with the recent availability of the un
folded distributions from BaBar analysis for all invariant hadronic masses
. The choice of this channel was motivated by its relatively large branch
ing ratio and the already non-trivial dynamics of three-pion final state.
A set of the hadronic currents within RChL for other final states with tw
o and three pseudoscalars is also installed in TAUOLA\n\nIn this talk we r
eview our results on the three-pion decay mode as well present a new fitti
ng framework. It allows to perform fits for an arbitrary tau decay mode\,
using either Fortran or C++ code. Using the new framework the theoretical
model parameters are fitted to the one-dimensional distributions provided
by the BaBar Collaboration\, in the case of the three meson decay modes\,
and to the Belle data\, for the two pion form factor. The results of the f
it are discussed. Based on the obtained results the pole mass of the invol
ved resonances are estimated.\n\nhttps://agenda.infn.it/event/7897/contrib
utions/70604/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70604/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Hadronic parity violation in effective field theory
DTSTART;VALUE=DATE-TIME:20150629T142000Z
DTEND;VALUE=DATE-TIME:20150629T144500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70603@agenda.infn.it
DESCRIPTION:Speakers: Matthias Schindler (University of South Carolina\, C
olumbia)\nParity-violating interactions between nucleons are the manifesta
tion of an interplay of strong and weak interactions between quarks in the
nucleons. Because of the short range of the weak interactions\, these par
ity-violating forces provide a unique probe of low-energy strong interacti
ons. An ongoing experimental program is mapping out this weak component of
the nuclear force in few-nucleon systems. Recent theoretical progress in
analyzing and interpreting hadronic parity violation in such systems\, bas
ed on effective field theory methods\, will be described. In particular\,
important information on parity-violating nucleon-nucleon interactions can
be gained from an asymmetry in deuteron photodisintegration\, which might
be measurable at a future high-intensity photon source such as the propos
ed upgraded HIGS facility. Recent theoretical calculations of this parity-
violating asymmetry and the impact of such a measurement on our understand
ing of hadronic parity violation will be discussed.\n\nhttps://agenda.infn
.it/event/7897/contributions/70603/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70603/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum Monte Carlo calculations of electromagnetic moments and tr
ansitions in A<=10 nuclei with two-body chiEFT currents
DTSTART;VALUE=DATE-TIME:20150702T153500Z
DTEND;VALUE=DATE-TIME:20150702T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70602@agenda.infn.it
DESCRIPTION:Speakers: Saori pastore (University of South Carolina\, Columb
ia)\nIn this talk\, I will present a number of Quantum Monte Carlo calcula
tions of electromagnetic observables in light nuclei (A\n\nhttps://agenda.
infn.it/event/7897/contributions/70602/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70602/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Recent developments in neutron-proton scattering with lattice effe
ctive field theory
DTSTART;VALUE=DATE-TIME:20150702T125500Z
DTEND;VALUE=DATE-TIME:20150702T131000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70601@agenda.infn.it
DESCRIPTION:Speakers: Jose Manuel Alarcon (University of Bonn)\nIn this ta
lk I want to present the recent progresses in neutron-proton scattering on
the lattice with Lattice EFT. Among them\, the study of the different lat
tice actions in describing the scattering observables and binding energy o
f the deuteron. The convergence of the chiral series for these observables
will be analyzed as well\, and will be shown to be in good agreement with
the expected behaviour of a perturbative approach. Finally\, I will comme
nt on the problem regarding the description of the mixing angle on the lat
tice\, which is one of the remaining problems since the beginning of the l
attice EFT calculations.\n\nhttps://agenda.infn.it/event/7897/contribution
s/70601/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70601/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Status of chiral-scale perturbation theory
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70600@agenda.infn.it
DESCRIPTION:Speakers: Rod Crewther (University of Adelaide)\nWe observe th
at flavor current conservation constrains the structure of chiral-scale pe
rturbation theory ChPT_sigma. This theory addresses the disagreement betwe
en experiment and lowest order chiral SU(3) x SU(3) perturbation theory (C
hPT_3) for amplitudes involving the f_0(500) resonance and O(m_K) extrapol
ations in momenta. In ChPT_sigma\, it is assumed that 3-flavor QCD has an
infrared fixed point where the chiral condensate induces nine Nambu-Goldst
one bosons: pi\, K\, eta and a QCD dilaton sigma which we identify with f
_0(500). In the leading order of ChPT_sigma\, dilaton-pole dominance expla
ins the Delta I = 1/2 rule in nonleptonic K-decays. The effect of the simp
lification noted above is that the theory becomes more predictive for the
decays sigma -> pi pi and sigma -> gamma gamma and hence for the sigma NN
coupling.\n\nhttps://agenda.infn.it/event/7897/contributions/70600/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70600/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral dynamics in the low-temperature phase of QCD
DTSTART;VALUE=DATE-TIME:20150702T151000Z
DTEND;VALUE=DATE-TIME:20150702T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70599@agenda.infn.it
DESCRIPTION:Speakers: Daniel Robaina (Institute of Nuclear Physics\, Mainz
)\nWe investigate the low-temperature phase of strongly interacting matter
and the crossover region with two light flavors of quarks in Lattice QCD.
Based on Chiral Ward Identities we test the applicability of a fixed-temp
erature chiral expansion given that chiral symmetry is spontaneously broke
n. It indicates that a sharp real-time excitation persists with the quantu
m numbers of the pion consistently with Goldstone's theorem even at T=150
MeV. We determine the real part of the pole and its residue in the axial-c
harge density correlator at zero and finite momentum. The time-dependent c
orrelators are also analyzed using the Maximum Entropy method and the Back
us-Gilbert method yielding consistent results. In addition\, we also test
the predictions of ordinary chiral perturbation theory around the point (T
=0\, m=0) for the temperature dependence of static observables. Around the
crossover region\, we find that all quantities considered depend only mil
dly on the quark mass in the range 8 MeV \n\nhttps://agenda.infn.it/event/
7897/contributions/70599/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70599/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scattering cluster wave functions on the lattice using the adiabat
ic projection method
DTSTART;VALUE=DATE-TIME:20150702T131000Z
DTEND;VALUE=DATE-TIME:20150702T132500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70598@agenda.infn.it
DESCRIPTION:Speakers: Alexander Rokash (Ruhr University\, Bochum)\nThe adi
abatic projection method is a general framework for obtaining low-energy e
ffective Hamiltonian for clusters. Previous studies [1\,2] have used the
adiabatic projection method in combination with the finite-volume energy L
uscher method to extract scattering phase shifts. We discuss several meth
ods to calculate elastic phase shifts directly from asymptotic cluster wav
e functions obtained from the effective cluster Hamiltonian for examples i
n one and three dimensions. This approach is less sensitive than the fini
te-volume energy Luscher method to stochastic and systematic errors which
appear in the application of the adiabatic projection method.\n\nReference
s\n1. M. Pine et al.\, Eur. Phys. J. A. 49 \, 151 (2013).\n2. S. Elhat
isari et al.\, Phys. Rev. C90 \, 064001 (2014)\n\nhttps://agenda.infn.it/
event/7897/contributions/70598/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70598/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The nuclear contact: From nucleus photodisintegration to nucleons
momentum distributions
DTSTART;VALUE=DATE-TIME:20150630T160000Z
DTEND;VALUE=DATE-TIME:20150630T161500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70597@agenda.infn.it
DESCRIPTION:Speakers: Betzalel Bazak (Racah Institute of Physics\, The Heb
rew University of Jerusalem)\nRecently\, Tan suggested that the properties
of universal quantum gases depend on a new characteristic quantity\, call
ed the contact. The contact describes the probability of two particles com
ing close to each other\, i.e. it is a measure of the number of close part
icle pairs in the system. Utilizing the contact\, this theory predicts the
energy\, pressure and other properties of the system. It was proven right
in a series of ultracold atomic experiments. We generalize Tan's contact
to nuclear systems\, introducing the various nuclear contacts\, taking in
to account all possible pair configurations. The leading neutron-proton co
ntact is then evaluated from medium energy photodisintegration experiments
. To this end\, the Levinger quasi-deuteron model of nuclear photodisinteg
ration is reformulated\, and the bridge between the Levinger constant and
the contact is established. Using experimental evaluations of Levinger's c
onstant the value of the neutron-proton contact in finite nuclei and in sy
mmetric nuclear matter is extracted\, and compared to the universal theory
. Utilizing the contact\, a new asymptotic connection between the one-nucl
eon and two-nucleon momentum distributions\, describing the two-body short
-range correlations in nuclei\, is obtained. Using available numerical dat
a\, we extract few connections between the different contacts and verify t
heir relations to the momentum distributions.\n\nhttps://agenda.infn.it/ev
ent/7897/contributions/70597/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70597/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nuclear electric dipole moment of light nuclei in the gaussian exp
ansion method
DTSTART;VALUE=DATE-TIME:20150702T145000Z
DTEND;VALUE=DATE-TIME:20150702T150500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70596@agenda.infn.it
DESCRIPTION:Speakers: Nodoka Yamanaka (iTHES Research Group\, RIKEN)\nThe
nuclear electric dipole moment is a very sensitive probe of CP violation b
eyond the standard model\, and for light nuclei\, it can be evaluated accu
rately using the few-body calculational methods. In this work\, we evaluat
e the electric dipole moment of the deuteron\, $^3$He\, $^3$H\, $^6$Li\, a
nd $^9$Be in the Gaussian expansion method with realistic nuclear force\,
and assuming the one-meson exchange model for the P\, CP-odd nuclear force
. We then give the future prospects for BSM models such as the supersymmet
ry within the prospective experimental sensitivity.\n\nhttps://agenda.infn
.it/event/7897/contributions/70596/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70596/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The a_0(980) revisited
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70595@agenda.infn.it
DESCRIPTION:Speakers: Thomas Wolkanowski-Gans (Goethe-Universität Frankfu
rt am Main)\nA way to understand the light scalar sector of hadron physics
is by applying a type of dynamical generation in which additional resonan
ces arise as companion poles from quark-antiquark seed states by incorpora
ting mesonic loops at the level of S-wave propagators [1−3]. Along this
line\, we ﬁrst repeat and complete the calculations of previous works of
Tornqvist and Roos (TR) and Boglione and Pennington (BP)\, where the reso
nance a0(980) appears as an additional pole of the propagator of the predo
minately quark-antiquark state a0(1450). Both works were important as they
demonstrated the feasibility of the idea of companion poles – however\,
we show that in TR\, the same as in BP\, the pole width of both states is
too large by a factor of 2 when compared to data\, and that in BP the pol
e mass of a0(1450) is too large of about 400 MeV. We then construct an e
ﬀective model Lagrangian for a0(1450) coupling to pseudoscalar mesons wi
th both non-derivative and derivative interactions\, and calculate its pro
pagator. We demonstrate that it is indeed possible to obtain two poles\, o
ne for a0(980) and one for a0(1450)\, in good agreement with data\, thus s
howing that the mechanism of companion poles can deliver not only qualitat
ive but also quantitative correct results.\n\nReferences\n1. N. A. Tornqvi
st\, Z. Phys. C 68\, 647 (1995).\n2. N. A. Tornqvist and M. Roos\, Phys. R
ev. Lett. 76\, 1575 (1996).\n3. M. Boglione and M. R. Pennington\, Phys. R
ev. D 65\, 114010 (2002).\n\nhttps://agenda.infn.it/event/7897/contributio
ns/70595/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70595/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Axial U(1) symmetry in the chiral symmetric phase of 2-flavor QCD
at finite temperature
DTSTART;VALUE=DATE-TIME:20150702T145000Z
DTEND;VALUE=DATE-TIME:20150702T151000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70594@agenda.infn.it
DESCRIPTION:Speakers: Sinya Aoki (Kyoto University)\nWe discuss the fate o
f the axial U(1) symmetry in 2-flavor QCD\, when the non-singlet chiral sy
mmetries are recovered at finite temperature. We theoretically investigate
the constraints on the eigenvalue density of the Dirac operator\, derived
from the non-singlet chiral symmetries among various multi-point correlat
ion functions in the chiral limit. We show that the axial U(1) symmetry\,
broken by the anomaly at low temperature\, is "effectively" recovered in t
he chiral symmetric phases of 2-flavor QCD above the critical temperature.
Here the effective recovery of the axial U(1) symmetry means\, for exampl
e\, that the susceptibility of non-singlet (pi) and singlet (eta) pseudo-s
calar mesons become identical in the symmetric phase\, which implies that
the axial U(1) anomaly is invisible in these channels. We next consider r
ecent numerical investigations on the axial U(1) symmetry in 2-flavor latt
ice QCD with exact lattice chiral symmetry\, which is shown to be crucial
for this problem. Numerical results in these study confirm our theoretical
expectation mentioned above. We finally discuss an implication of our re
sults to the phase structure of lattice QCD at finite temperature.\n\nhttp
s://agenda.infn.it/event/7897/contributions/70594/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70594/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Isospin breaking effects in the K^+_{e4} decays
DTSTART;VALUE=DATE-TIME:20150629T134000Z
DTEND;VALUE=DATE-TIME:20150629T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70593@agenda.infn.it
DESCRIPTION:Speakers: Marc Knecht (CNRS/CPT\, Marseille)\nThe very precise
data obtained by the NA48/2 collaboration at the CERN SPS on the decay ch
annels K^\\pm \\to \\pi^+ \\pi^- e^\\pm \\stackrel{_{(-)}}{\\nu_e}$ and $K
^\\pm \\to \\pi^0 \\pi^0 e^\\pm \\stackrel{_{(-)}}{\\nu_e}$ have made it n
ecessary to address issues related to isospin breaking. Three aspects rela
ted to this issue will be considered: isospin breaking due to the pion ma
ss difference in the phases of the form factors for the $K^\\pm \\to \\pi^
+ \\pi^- e^\\pm \\stackrel{_{(-)}}{\\nu_e}$ decay amplitude\, the cusp in
the decay distribution of the $K^\\pm \\to \\pi^0 \\pi^0 e^\\pm \\stackrel
{_{(-)}}{\\nu_e}$ mode\, and radiative corrections.\n\nhttps://agenda.infn
.it/event/7897/contributions/70593/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70593/
END:VEVENT
BEGIN:VEVENT
SUMMARY:SU(3) flavor breaking in baryon octet light-cone distribution ampl
itudes
DTSTART;VALUE=DATE-TIME:20150702T134000Z
DTEND;VALUE=DATE-TIME:20150702T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70592@agenda.infn.it
DESCRIPTION:Speakers: Philipp Wein (University of Regensburg)\nWe present
a leading one-loop calculation in the framework of three-flavor baryon chi
ral perturbation theory (BChPT) for three-quark light-cone distribution am
plitudes\, which parametrize the momentum distribution in the leading Fock
state and are relevant for the description of hard exclusive processes. S
uch a calculation automatically yields model-independent results for the l
eading SU(3) flavor breaking effects. It is possible to find a minimal set
of distribution amplitudes (DAs) that do not mix under chiral extrapolati
on towards the physical point and naturally embed the $\\Lambda$ baryon. F
or the wave function normalization constants and for the first moments of
the leading twist DA we will provide first results obtained from fits to p
reliminary lattice QCD data.\n\nhttps://agenda.infn.it/event/7897/contribu
tions/70592/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70592/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extraction of low energy QCD parameters from eta to 3pi and beyond
DTSTART;VALUE=DATE-TIME:20150630T130000Z
DTEND;VALUE=DATE-TIME:20150630T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70591@agenda.infn.it
DESCRIPTION:Speakers: Marián Kolesár (IPNP\, Charles University\, Prague
)\nThe eta to 3pi decays are a valuable source of information on low energ
y QCD. Yet they were not used for an extraction of the three flavor chiral
symmetry breaking order parameters until now. We use a bayesian approach
in the framework of resummed chiral perturbation theory to extract informa
tion on the quark condensate and pseudoscalar decay constant in the chiral
limit\, as well as the mass difference of the light quarks. We compare ou
r results with recent CHPT and lattice QCD fits and find some tension\, as
the eta to 3pi data seem to prefer a larger ratio of the chiral order par
ameters. The results also seem to exclude a large value of the chiral deca
y constant\, which was found by some recent works. In addition\, we presen
t preliminary results of a combined analysis including eta to 3pi decays a
nd pi-pi scattering.\n\nhttps://agenda.infn.it/event/7897/contributions/70
591/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70591/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constraints on the chiral unitary KN amplitude from πΣK photopro
duction data
DTSTART;VALUE=DATE-TIME:20150702T145000Z
DTEND;VALUE=DATE-TIME:20150702T151000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70590@agenda.infn.it
DESCRIPTION:Speakers: Maxim Mai (HISKP\, University of Bonn)\nA chiral uni
tary approach for antikaon-nucleon scattering in on-shell factorization is
studied. We find multiple sets of parameters for which the model describe
s all existing hadronic data similarly well. We confirm the two-pole struc
ture of the Λ(1405). The narrow Λ(1405) pole appears at comparable posit
ions in the complex energy plane\, whereas the location of the broad pole
suffers from a large uncertainty. In the second step\, we use a simple mod
el for photoproduction of K+ πΣ off the proton and confront it with the
experimental data from the CLAS Collaboration. It is found that only a few
of the hadronic solutions allow for a consistent description of the CLAS
data within the assumed reaction mechanism.\n\nhttps://agenda.infn.it/even
t/7897/contributions/70590/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70590/
END:VEVENT
BEGIN:VEVENT
SUMMARY:pi0: the lightest hadron
DTSTART;VALUE=DATE-TIME:20150702T161000Z
DTEND;VALUE=DATE-TIME:20150702T163000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70589@agenda.infn.it
DESCRIPTION:Speakers: Karol Kampf (Charles University\, Prague)\nIn this t
alk I will present basic properties of the lightest meson\, pi0. I will di
scuss its decay modes\, mainly two photon decay\, Dalitz decay and e+e- pr
oduction and focus on its recent theoretical and experimental studies. Con
nection with the theoretical calculation of the hadronic light-by-light sc
attering contribution in the g-2 type experiment will be outlined.\n\nhttp
s://agenda.infn.it/event/7897/contributions/70589/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70589/
END:VEVENT
BEGIN:VEVENT
SUMMARY:K-pi scattering lengths from lattice QCD
DTSTART;VALUE=DATE-TIME:20150629T152000Z
DTEND;VALUE=DATE-TIME:20150629T154000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70588@agenda.infn.it
DESCRIPTION:Speakers: Tadeusz Janowski (University of Southampton)\nWe pre
sent the recent lattice QCD calculation of K-π I=3/2 and I=1/2 scattering
lengths by the RBC-UKQCD collaboration. Our calculation is the first latt
ice calculation of these quantities performed using physical point ensembl
es [1]. This allows us to bypass the error due to chiral extrapolation\, w
hich in current calculations is the dominant source of systematic errors [
2\,3\,4\,5]. Preliminary results are presented and compared to those from
earlier studies which were obtained at heavier pion masses and extrapolate
d to the physical point.\n\nReferences\n1. T. Blum et al. [RBC and UKQCD C
ollaborations]\, “Domain wall QCD with physical quark masses\,” arXiv:
1411.7017 [hep-lat]\n2. S. R. Beane\, P. F. Bedaque\, T. C. Luu\, K. Orgin
os\, E. Pallante\, A. Parreno and M. J. Savage\, Phys. Rev. D 74 (2006) 11
4503 [hep-lat/0607036].\n3. Z. Fu\, JHEP 1201 (2012) 017 [arXiv:1110.5975
[hep-lat]].\n4. Z. Fu\, Phys. Rev. D 85 (2012) 074501 [arXiv:1110.1422 [he
p-lat]].\n5. K. Sasaki et al. [PACS-CS Collaboration]\, Phys. Rev. D 89(20
14) 054502 [arXiv:1311.7226[hep-lat]].\n\nhttps://agenda.infn.it/event/789
7/contributions/70588/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70588/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Studies of Lambda-neutron interaction through polarization observa
bles for final-state interactions in exclusive Lambda photoproduction off
the deuteron
DTSTART;VALUE=DATE-TIME:20150630T151500Z
DTEND;VALUE=DATE-TIME:20150630T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70587@agenda.infn.it
DESCRIPTION:Speakers: Yordanka Ilieva (University of South Carolina\, Colu
mbia)\nTheoretical studies suggest that experimental observables for hyper
on production reactions can place stringent constraints on the free parame
ters of hyperon-nucleon potentials\, which are critical for the understand
ing of hypernuclear matter and neutron stars. We will present preliminary
experimental results for the polarization observables Σ\, Py\, Ox\, Oz\,
Cx\, and Cz for final-state interactions (FSI) in exclusive Lambda photopr
oduction off the deuteron. The observables were obtained from data collect
ed during the E06-103 (g13) experiment with the CEBAF Large Acceptance Spe
ctrometer in Hall B at Jefferson Lab. The g13 experiment ran with unpolari
zed deuteron target and circularly- and linearly-polarized photon beams wi
th energies between 0.5 GeV and 2.5 GeV and collected about 5×1010 events
with multiple charged particles in the final state. To select the reactio
n of interest\, the kaon and Lambda decay products\, a proton and a negati
ve pion\, were detected in CLAS. Missing-mass technique was used to furthe
r reduce the event sample. Final-state interaction events were selected by
requesting that the reconstructed neutron has a momentum larger than 200
MeV/c. The large statistics of E06-103 provided statistically meaningful F
SI event samples\, which allow for the extraction of one- and two-fold dif
ferential single- and double-polarization observables. In this talk we wil
l show preliminary results for a set of six observables for photon energie
s between 0.9 GeV and 2.3 GeV and for several kinematic variables in the L
ambda-neutron center-of-mass frame. Comparison with theoretical calculatio
ns will also be discussed. Our results are the very first measurements of
polarization observables for FSI in hyperon photoproduction and will be us
ed to constrain the free parameters of hyperon-nucleon potentials.\n\nhttp
s://agenda.infn.it/event/7897/contributions/70587/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70587/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joint Physics Analysis Center Activities
DTSTART;VALUE=DATE-TIME:20150630T134000Z
DTEND;VALUE=DATE-TIME:20150630T140000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70586@agenda.infn.it
DESCRIPTION:Speakers: Vincent Mathieu (Indiana University\, Bloomington)\n
The Joint Physics Analysis Center gathers theorists working on tools devel
opment for the analysis of hadon spectroscopy experiments. Our aim is to p
rovide to experimentalists flexible amplitudes to fit data and easily extr
act the physics of a specific reaction. I will report on the latest result
s including pion-nucleon and kaon-nucleon elastic scattering\, eta/omega/p
hi mesons decays in three pions and photoproduction on strange mesons.\n\n
https://agenda.infn.it/event/7897/contributions/70586/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70586/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hypernuclear decay of strangeness -2 hypernuclei
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70585@agenda.infn.it
DESCRIPTION:Speakers: Jordi Maneu (University of Barcelona)\nSince the dis
covery in 1952 of the first strange fragment in emulsion chamber experimen
ts\, many efforts have been put in extending our knowledge of the nuclear
chart\, including the SU(3) sector. Worldwide\, the study of the interact
ions among nucleons and hyperons has been a priority in the research plan
of many experimental facilities. After more than sixty years of Λ-hypernu
clear studies\, some attention has moved to more strange systems\, with th
e production of ΛΛ-hypernuclei and more recently\, with proposals to stu
dy Ξ-hypernuclear spectroscopy.\n\nOur main objective is to calculate the
decay rate for the weak decay of ΛΛ-hypernuclei\, including all the int
ermediate baryonic channels allowed by the strong interaction. I will focu
s on the analysis of the decay induced by the Λ hyperon\, i.e.\, starting
with a ΛΛ pair. The weak decay mechanism describing the two-body weak
interaction is modelled by the exchange of mesons belonging to the ground
state of pseudoscalar and vector octets. The tree-level values for the bar
yon-baryon-meson coupling constants are derived using SU(3) symmetry for p
seudoscalar mesons and the Hidden Local Symmetry for vector mesons. In the
computation of the decay rate\, the effects of the strong interaction on
the initial state are introduced through the solution of a G-matrix equati
on\, with the input of realistic baryon-baryon potentials\, while the fina
l hyperon-nucleon wavefunctions are obtained in an analogous way\, by solv
ing the corresponding T-matrix equation.\n\nhttps://agenda.infn.it/event/7
897/contributions/70585/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70585/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Hermes results on 3D imaging of the nucleon
DTSTART;VALUE=DATE-TIME:20150702T123000Z
DTEND;VALUE=DATE-TIME:20150702T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70584@agenda.infn.it
DESCRIPTION:Speakers: Luciano Libero Pappalardo (INFN-Ferrara)\nIn the con
text of rapid theoretical developments in non-perturbative QCD\, a formali
sm of Transverse Momentum Dependent parton distribution functions (TMDs) a
nd of Generalized Parton Distributions (GPDs) was introduced in the last t
wo decades\, providing a more comprehensive multi-dimensional description
of the nucleon. TMDs and GPDs allow in fact for complementary descriptions
of the nucleon in three dimensions (nucleon tomography)\, spanned by the
quarks longitudinal momenta and\, respectively\, by the their transverse m
omenta components and transverse spatial coordinates. They thus contribute
\, with different approaches\, to the full phase-space description of the
nucleon structure. Furthermore\, they provide complementary insights into
the yet unmeasured quark orbital angular momentum. Experimentally\, TMDs a
nd GPDs can be accessed through the analysis of specific azimuthal asymmet
ries measured\, respectively\, in semi-inclusive deep-inelastic scattering
and hard exclusive processes\, such as hard leptoproduction of real photo
ns or mesons. The HERMES experiment has collected wealth of data on scatte
ring of a longitudinally polarized lepton (electron or positron) beam from
HERA off unpolarized\, longitudinally and transversely polarized internal
gas targets. Collected data allowed to measure a variety of asymmetries w
ith respect to beam charge\, beam helicity and target polarization. A sele
ction of HERMES results on observables sensitive to TMDs and GPDs will be
presented.\n\nhttps://agenda.infn.it/event/7897/contributions/70584/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70584/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elastic nucleon-deuteron scattering and breakup with chiral forces
DTSTART;VALUE=DATE-TIME:20150630T133000Z
DTEND;VALUE=DATE-TIME:20150630T134500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70583@agenda.infn.it
DESCRIPTION:Speakers: Henryk witala (Jagiellonian University\, Krakow)\nCo
mparison of theoretical predictions based on a nucleon-nucleon potential w
ith data for elastic nucleon-deuteron (Nd) scattering and nucleon induced
deuteron breakup reveals the importance of the three-nucleon force (3NF).
Inclusion of semi-phenomenological 3NF models into calculations in many ca
ses improves the data description. However\, some serious discrepancies re
main even when 3NF is included. At low energies the prominent examples wer
e found for the vector analyzing power in elastic Nd scattering and for th
e neutron-deuteron (nd) breakup cross sections in neutron-neutron (nn) qua
si-free-scattering (QFS) and symmetric-space-star (SST) geometries [1]. Si
nce both these conﬁgurations depend predominantly on the S-wave nucleon-
nucleon (NN) force components\, these cross section discrepancies have ser
ious consequences for the nn 1S0 force component. At energies above ≈ 10
0 MeV current 3NF’s only partially improve the description of data for c
ross section and spin observables in elastic Nd scattering and breakup. Th
e complex angular and energy behavior of analyzing powers\, spin correlati
on and spin transfer coefﬁcients fails to be explained by standard nucle
on-nucleon interactions alone or combined with current models of 3NF’s [
2-3]. One of the reasons for the above disagreements could be a lack of co
nsistency between 2N and 3N phenomenological potentials used or/and omissi
on of important terms in the applied 3NF. The Chiral Eﬀective Field Theo
ry approach provides consistent two- and three-nucleon forces. The 3NF occ
urs for the ﬁrst time at next-to-next-to leading order (N2LO) of chiral
expansion. The chiral NN potentials have been constructed up to N4LO order
of chiral expansion [4]. The N3LO and N4LO NN forces when used in 3N calc
ulations provide description of NN data of the same quality as standard\,
realistic NN potentials. The chiral 3NF at N3LO\, derived recently\, consi
sts of long range parts with the 2π-exchange\, 1π-2π and ring terms [5]
and a short-range contributions 2π-contact and relativistic corrections
of order 1/m [6]. This is supplemented by 1π- and 3N- contact terms. Prel
iminary results obtained with chiral forces for elastic Nd scattering and
breakup will be presented.\n\nReferences\n1. H. Witala et al.\, Phys. Rev.
C 83\, 034004 (2011).\n2. Y. Maeda et al.\, Phys. Rev. C 76\, 014004 (200
7).\n3. K. Sekiguchi et al.\, Phys. Rev. C 79\, 054008 (2009).\n4. E. Epel
baum et al.\, arXiv:14.12.4623.\n5. V. Bernard et al.\, Phys. Rev. C 77\,
064004 (2008).\n6. V. Bernard et al.\, Phys. Rev. C 84\, 054001 (2011).\n\
nhttps://agenda.infn.it/event/7897/contributions/70583/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70583/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constraints on the ωπ form factor from analyticity and unitarity
DTSTART;VALUE=DATE-TIME:20150629T150000Z
DTEND;VALUE=DATE-TIME:20150629T152000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70582@agenda.infn.it
DESCRIPTION:Speakers: Balasubramanian Ananthanarayan (Indian Institute of
Science\, Bengaluru)\nMotivated by the discrepancies noted recently betwee
n the theoretical calculations of the electromagnetic ωπ form factor and
certain experimental data\, we investigate this form factor using analyti
city and unitarity in a framework known as the method of unitarity bounds.
We use a QCD correlator computed on the spacelike axis by operator produc
t expansion and perturbative QCD as input\, and exploit unitarity and the
positivity of its spectral function\, including the two-pion contribution
that can be reliably calculated using high-precision data on the pion form
factor. From this information\, we derive upper and lower bounds on the m
odulus of the ωπ form factor in the elastic region. The results provide
a significant check on those obtained with standard dispersion relations\,
confirming the existence of a disagreement with experimental data in the
region around 0.6GeV .\n\nhttps://agenda.infn.it/event/7897/contributions/
70582/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70582/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nuclear axial current in chiral effective field theory
DTSTART;VALUE=DATE-TIME:20150629T150000Z
DTEND;VALUE=DATE-TIME:20150629T151500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70581@agenda.infn.it
DESCRIPTION:Speakers: Alessandro Baroni (Old Dominion University\, Norfolk
)\nWe present the derivation of two-nucleon axial charge and current opera
tors in chiral effective field theory up to order Q in the power counting\
, where Q denotes generically the low momentum scale. The derivation is ba
sed on time-ordered perturbation theory\, and accounts for cancellations b
etween the contributions of irreducible diagrams and those due to non-stat
ic corrections from energy denominators of reducible diagrams. Renormalize
d terms in the axial charge are obtained by isolating divergences in loop
corrections via dimensional regularization\, and reabsorbing them in a sub
set of the low-energy constants of contact operators entering the theory a
t order Q. The axial current contains no divergencies at order Q and also
no contact terms at this order.\n\nhttps://agenda.infn.it/event/7897/contr
ibutions/70581/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70581/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effective theory for lattice nuclei
DTSTART;VALUE=DATE-TIME:20150629T131000Z
DTEND;VALUE=DATE-TIME:20150629T132500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70580@agenda.infn.it
DESCRIPTION:Speakers: Lorenzo Contessi (TIFP\, Trento)\nIn the last years
Lattice QCD has substantially improved its predictive power for light nucl
ei [1\,2\,3]. Now we have access to data for light nuclei in systems with
high pionic mass. We argue that the proper low-energy theory is a contact
(or pionless) approach\, since for these systems pion effects are of short
-range. By means of this effective theory it is possible to extend LQCD pr
edictions to heavier nuclei. The low energy constants of the theory at lea
ding order can be determined using LQCD data of binding energy of deuteron
\, triton and helion. I will present predictions [4] for binding energy of
4He\, 5He\, 5Li and 6Li calculated with effective-interaction hyperspheri
cal harmonics (EIHH) and auxiliary field diffusion Montecarlo (AFDMC)\, th
en discuss the extension of the method\, done with AFDMC\, for much heavie
r nuclei. In this way we illustrate for the first time how to make predict
ions on nuclei starting from LQCD results\, anticipating the procedure tha
t should be adopted with chiral dynamics\, once LQCD will be able to give
results with smaller pion mass.\n\nReferences\n1. T. Yamazaki\, K. Ishikaw
a\, Y. Kuramashi\, and A. Ukawa\, Phys. Rev. D 86 (2012) 074514.\n2. S.R.
Beane et al. (NPLQCD Collaboration)\, Phys. Rev. D 87 (2013) 034506.\n3. S
.R. Beane et al. (NPLQCD Collaboration)\, Phys. Rev. C 88 (2013) 024003.\n
4. N. Barnea\, L. Contessi\, D. Gazit\, F. Pederiva and U. van Kolck\, Phy
s. Rev. Lett. 114 (2015) 5\, 052501\n\nhttps://agenda.infn.it/event/7897/c
ontributions/70580/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70580/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Uncertainty quantification and chiral dynamics
DTSTART;VALUE=DATE-TIME:20150630T142000Z
DTEND;VALUE=DATE-TIME:20150630T144500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70579@agenda.infn.it
DESCRIPTION:Speakers: Daniel Phillips (Ohio University\, Athens)\nI will s
how that combining effective field theories (EFTs) with Bayesian data anal
ysis facilitates the rigorous quantification of theoretical uncertainties
[1]. Bayesian methods are sometimes attacked on the grounds that the use o
f priors produces a subjective result. I will argue that\, in fact\, incor
porating priors in the analysis permits the consistent application of anal
ysis assumptions that are otherwise only implicit or imposed in an ad hoc
way. In a Bayesian framework such assumptions can then be tested\, and\, i
f necessary\, modified in light of new information.\n\nIn this talk the ge
neral framework for incorporating Bayesian priors that encode the expectat
ion that low-energy coefficients (LECs) in the EFT are natural will first
be presented. Applications such as:\n\n-computation of higher-order uncert
ainties in chiral EFT calculations of NN scattering [2]\;\n-the extraction
of low-energy constants in toy models designed to mimic EFTs with both na
tural and unnatural coefficients [3]\;\n-the extrapolation of lattice data
on the nucleon mass to the physical pion mass\n\nwill be discussed. \n\nT
his work was performed by the BUQEYE collaboration and is supported by the
National Science Foundation and the US Department of Energy. \n\n[1] A re
cipe for EFT uncertainty quantification in nuclear physics\, R.J. Furnstah
l\, D.R. Phillips\, S. Wesolowski\, J. Phys. G42 (2015) 3\, 034028.\n\n[2]
R.J. Furnstahl\, N. Klco\, D.R. Phillips\, S. Wesolowski\, in preparation
.\n\n[3] S. Wesolowski\, N. Klco\, A. Thapaliya\, R. J. Furnstahl\, D. R.
Phillips\, in preparation.\n\nhttps://agenda.infn.it/event/7897/contributi
ons/70579/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70579/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of the electroweak processes in the two and three-nucleon sy
stems with local chiral forces.
DTSTART;VALUE=DATE-TIME:20150702T150500Z
DTEND;VALUE=DATE-TIME:20150702T152000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70578@agenda.infn.it
DESCRIPTION:Speakers: Roman Skibinski (Jagiellonian University\, Krakow)\n
In the recent decade the chiral Eﬀective Field Theory (χEFT) has proven
its predictive power in low energy nuclear physics. Within this approach
the two- and three-nucleon (3N) forces have been derived perturbatively in
a consistent manner [1\,2]. The three-nucleon force (3NF) occurs for the
ﬁrst time at the next-to-next-to leading order (N2LO) of chiral expansio
n. Inclusion of N2LO 3NF to study three-nucleon processes has revealed an
overall good agreement between theoretical predictions and data [3]. The q
uality of data description is similar to those obtained with semi-phenomen
ological potentials. The remaining discrepancies are partially related to
poor spin structure of these chiral forces. The further improvement in dat
a description is expected when higher order chiral forces will be taken in
to account. Unfortunately\, the 3NF at the next order (N3LO) has much more
complex structure [4\,5] and its inclusion in theoretical studies is much
more challenging. In recent papers [6\,7] we have studied the role of ful
l chiral N3LO 3NF in a description of the nucleon-deuteron elastic scatter
ing and the deuteron breakup and found no improvement in data description.
Moreover unnaturally large values of the two free parameters (low energy
constants) of this 3NF have to be used to describe 3H binding energy and t
he neutron-deuteron doublet scattering length. The studies [6\,7] already
accelerated work on the new generation of chiral NN and 3N forces. Recentl
y\, the improved chiral NN potentials up to N3LO [8] and N4LO [9] have bee
n derived by E.Epelbaum and collaborators. The most interesting feature of
theses forces is avsubstantial reduction of the cut-oﬀ artifacts in com
parison with the older models used in [6\,7]. In this contribution the ﬁ
rst results obtained with these very new forces up to N4LO for the deutero
n photodisintegration process\, the nucleon-deuteron radiative capture and
the muon capture on the 3He will be reported. Since the consistent chiral
nuclear electro-magnetic and weak currents are not available yet\, we hav
e included the electromagnetic meson exchange currents via the Siegert the
orem. In all cases the convergence of the theoretical predictions in respe
ct to chiral expansion as well as the dependence of predictions on cut-o
ﬀ parameters of the used forces will be discussed.\n\nReferences\n1. E.
Epelbaum\, H.-W. Hammer\, Ulf-G. Meißner\, Rev.Mod.Phys. 81\, 1773 (2009)
.\n2. R. Machleidt\, D.R. Entem\, Phys. Rept. 503\, 1 (2011).\n3. E. Epelb
aum et al.\, Phys. Rev. C66\, 064001 (2002).\n4. V. Bernard et al.\, Phys.
Rev. C77\, 064004 (2008).\n5. V. Bernard et al.\, Phys. Rev. C84\, 054001
(2011).\n6. H. Witala et al\, J. Phys. G: Nucl. Part. Phys. 41\, 094011 (
2014).\n7. J. Golak et al.\, Eur. Phys. J. A50\, 177 (2014).\n8. E. Epelba
um et al.\, arXiv:1412.0142 [nucl-th].\n9. E. Epelbaum et al.\, arXiv:1412
.4623 [nucl-th].\n\nhttps://agenda.infn.it/event/7897/contributions/70578/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70578/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Compton scattering and nucleon polarisabilities in
chiral EFT: The next steps
DTSTART;VALUE=DATE-TIME:20150629T142000Z
DTEND;VALUE=DATE-TIME:20150629T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70577@agenda.infn.it
DESCRIPTION:Speakers: Harald W. Griesshammer (George Washington University
\, Washington)\nCompton scattering from protons and neutrons probes the tw
o-photon response of the nucleon in electric and magnetic fields at fixed
photon frequency and multipolarity [1]. It provides detailed tests of the
symmetries and strengths of the interactions of the nucleonic constituents
with each other and with photons. Proton-neutron differences explore the
interplay between chiral symmetry breaking and short-distance Physics. At
low energies\, the process is parametrised by six energy-dependent dipole
polarisabilities. For convenience\, the information is however often compr
essed into the two scalar dipole polarisabilities αE1 and βM1 at the sta
tic point. In combination with emerging lattice QCD determinations\, they
provide stringent tests for our theoretical description of hadron structur
e. A plenary talk by J. A. McGovern discusses new high-accuracy extraction
s of the proton and neutron static electric and magnetic scalar dipole pol
arisabilities from all published elastic data below 300 MeV in Chiral EFT
with explicit ∆(1232) degrees of freedom and model-independent estimates
of higher-order corrections [2\,3].\n\nThis contribution addresses opport
unities for χEFT to serve as intermediary between first-principle calcula
tions in lattice QCD and efforts which are ongoing or approved at MAX-lab\
, HIγS and MAMI (cf. E. Downie’s plenary talk). Such high-intensity exp
eriments with polarised targets and polarised beams allow the extraction n
ot only of scalar polarisabilities\, but in particular of the so-far poorl
y explored spin-polarisabilities which parametrise the stiffness of the nu
cleon spin in external electro-magnetic fields (nucleonic bi-refringence/F
araday effect). New chiral predictions for a comprehensive study of proton
\, deuteron and 3He observables extend the analysis to higher energies and
higher orders and help to better determine spin and neutron polarisabilit
ies [4\,5]. They also serve to relate emerging lattice QCD simulations at
m_π > 200 MeV to data at the physical point. In chiral lattice extrapolat
ions\, the relative theoretical uncertainties increase with m_π: the magn
itudes of the polarisabilities decrease\; the χEFT expansion parameter it
self increases\; and the ∆(1232) becomes more important\, leading to a r
e-ordering of contributions. We quantify such uncertainties using a widely
applicable method and compare to existing simulations [6].\n\n\nReference
s\n1. H. W. Grießhammer\, J. A. McGovern\, D. R. Phillips and G. Feldman\
, Prog. Part. Nucl. Phys. 67 (2012) 841.\n2. J. A. McGovern\, D. R. Philli
ps and H. W. Grießhammer\, Eur. Phys. J. A49 (2013) 12.\n3. L. S. Myers e
t al.\, Phys. Rev. Lett. 113 (2014) 262506.\n4. H. W. Grießhammer\, Eur.
Phys. J. A49 (2013) 100.\n5. B. Sandberg\, H. W. Grießhammer\, J. A. McGo
vern and D. R. Phillips\, forthcoming.\n6. H. W. Grießhammer\, J. A. McGo
vern and D. R. Phillips\, forthcoming.\n\nhttps://agenda.infn.it/event/789
7/contributions/70577/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70577/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Evolution of the K-bar N - pi Sigma system with M^2_pi in a box fr
om UχPT
DTSTART;VALUE=DATE-TIME:20150702T153000Z
DTEND;VALUE=DATE-TIME:20150702T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70576@agenda.infn.it
DESCRIPTION:Speakers: Raquel Molina (The George Washington University\, Wa
shington)\nThe Λ(1405) baryon is of continued interest in hadronic physic
s\, being absent in many quark model calculations and supposedly manifesti
ng itself in a two-pole structure. Finite- volume Lattice-QCD eigenvalues
for different quark masses were recently reported by the Adelaide group [1
]. We compare these eigenvalues to those of a unitary Chiral Perturbation
Theory (UχPT) model [2]\, evaluated in the finite volume [3]. The UχPT c
alculation predicts the quark mass dependence remarkably well. It also exp
lains the overlap pattern with diﬀerent meson-baryon components\, mainly
πΣ and K-bar N\, at different quark masses. Some of the results of our
calculation are shown in Fig. 1. We will study the properties of the two l
ower states in the box as predicted by UχPT and compare to those of the t
wo poles of the Λ(1405) in the infinite limit. More accurate Lattice QCD
are required to draw definite conclusions on the nature of the Λ(1405).\n
\nReferences\n[1] J. M. M. Hall\, W. Kamleh\, D. B. Leinweber\, B. J. Mena
due\, B. J. Owen\, A. W. Thomas and R. D. Young\, Phys. Rev. Lett. 114\, n
o. 13\, 132002 (2015)\n[2] E. Oset\, A. Ramos and C. Bennhold\, Phys. Lett
. B 527\, 99 (2002) [Phys. Lett. B 530\, 260 (2002)]\n[3] M. Doring\, J. H
aidenbauer\, U. G. Meissner and A. Rusetsky\, Eur. Phys. J. A 47\, 163 (20
11)\n\nhttps://agenda.infn.it/event/7897/contributions/70576/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70576/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Progress in the quest for a realistic three-nucleon force
DTSTART;VALUE=DATE-TIME:20150630T131500Z
DTEND;VALUE=DATE-TIME:20150630T133000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70575@agenda.infn.it
DESCRIPTION:Speakers: Luca Girlanda (Universita del Salento\, Lecce & INFN
-Lecce)\nDespite long-lasting efforts in the determination of a realistic
three-nucleon force (TNF)\, none of the presently available models leads t
o a satisfactory description of bound and scattering states of the $A=3$ s
ystem. It seems natural to ascribe the above situation to the fact that t
hese models include a very small number of adjustable parameters\, compare
d to the two-nucleon interaction case. For example\, in the framework of t
he chiral expansion\, only 2 low-energy constants (LECs) enter up to and i
ncluding N3LO. At the following order (N4LO) one encounters 10 additional
LECs\, which parametrize the short-range component of the TNF\, and are un
constrained by chiral symmetry. As such\, they could provide the necessary
flexibility to arrive at a truly realistic model for the TNF. In this co
ntribution we will report about our progress along these lines. In particu
lar we examine to which extent the AV18 $NN$ interaction\, supplemented by
the leading and subleading contact-range TNF\, provides a satisfactory fi
t to $N-d$ scattering data.\n\nhttps://agenda.infn.it/event/7897/contribut
ions/70575/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70575/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Assessing theory errors using residual cutoff dependence
DTSTART;VALUE=DATE-TIME:20150630T144500Z
DTEND;VALUE=DATE-TIME:20150630T150000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70574@agenda.infn.it
DESCRIPTION:Speakers: Harald W. Griesshammer (George Washington University
\, Washington)\nThe past few years have witnessed a renewed emphasis of th
e need to quantify residual theoretical uncertainties [1\,2]. Ideally\,
“double-blind” calculations would assess them based on input and metho
d\, and not by comparison to data. This is particularly important if data
is absent or its consistency needs to be checked. Effective Field Theories
promise a well-defined scheme to provide such reproducible\, objective\,
quantitative error estimates. While straightforward in a perturbative EFT
like the purely mesonic or one-baryon sector of χEFT\, how can one valida
te the expansion in a non-perturbative EFT? This is a particularly nagging
question for few-nucleon systems\, where a fully consistent chiral EFT is
still under development since the NN interaction is non-perturbative\, le
ading to heated discussions which of the proposed power countings is consi
stent. A reliable uncertainty estimate is not just a cornerstone of the Ef
fective Field Theory methodology. To be able to falsify predictions of a t
heory is central to the Scientific Method. This talk proposes a means to c
heck the internal consistency of a non-perturbative expansion on a semi-qu
antitative level. One can indeed quantify the consistency of an EFT from t
he dependence of observables O(k\; Λ) at low momentum k on the cutoff Λ
employed in numerical calculations [2]. This way\, one actually turns into
an advantage the annoying fact that most nonperturbative systems do not a
llow for closed-form calculations. The power-counting in the small\, dimen
sion-less quantity Q ∝ k of an EFT predicts (up to logarithmic correctio
ns)\n\n 1 − O(k\; Λ1)/O(k\; Λ2) ∝ ( k/Λ_EFT)^{n+1}
(1)\n\nfor a calculation at order Qn \, where ¯ Λ_EFT is th
e typical high-energy scale at which the\nEFT description breaks down [3].
The slope of a double-logarithmic plot of a suitable quantity against k r
eveals thus the order of accuracy n and an estimate of Λ_EFT. In contradi
stinction to a method proposed by Lepage [4] \, this approach does not com
pare to data to assess uncertainties. The method is not the solution to al
l problems but another arrow in the quiver. Its advantages and shortcoming
s are discussed with various examples\, including some from recent literat
ure.\n\nReferences\n1. Editorial\, Phys. Rev. A83 (2011) 040001.\n2. J. Ph
ys. G42 (issue 3\, Feb 2015): Special Focus Issue “Enhancing the Interac
tion between Nuclear Experiment and Theory through Information and Statist
ics”.\n3. H. W. Grießhammer\, Nucl. Phys. A744 (2004) 192\, and forthco
ming.\n4. G. P. Lepage\, nucl-th/9706029.\n\nhttps://agenda.infn.it/event/
7897/contributions/70574/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70574/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading talk* K->pipi decays and the Delta I = 1/2 rule
DTSTART;VALUE=DATE-TIME:20150629T123000Z
DTEND;VALUE=DATE-TIME:20150629T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70573@agenda.infn.it
DESCRIPTION:Speakers: Nicolas Garron (Plymouth University)\nCP violation w
as discovered in Kaon decays 50 years ago but still remains a challenge fo
r theorists. A complete theoretical description will be a crucial test for
the Standard Model and will provide us with a rich source of information
on new physics theories. In the past recent years\, realistic computations
of A2\, the amplitude of K->(pipi)_(I=2)\, have become possible and reach
ed a level of 10% accuracy. I will explain how this computation has become
possible and will report on the other channel\, much more challenging\, i
n which the two-pion state has isospin I=0. I will also report on a possib
le explanation for the Delta I = 1/2 rule\, the fact the magnitude of the
amplitude A0 is around 20 times larger than the one of A2\, although a nai
ve computation only gives a factor of 2.\n\nhttps://agenda.infn.it/event/7
897/contributions/70573/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70573/
END:VEVENT
BEGIN:VEVENT
SUMMARY:a_0-f_0 mixing in the Khuri-Treiman equations for eta -> 3pi
DTSTART;VALUE=DATE-TIME:20150630T132000Z
DTEND;VALUE=DATE-TIME:20150630T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70572@agenda.infn.it
DESCRIPTION:Speakers: Bachir Moussallam (IPN\, Université Paris-Sud)\nThe
isospin violating eta->3pi decays are expected to provide the best observ
ables for the determination of the u-d quark mass difference. However\, us
ing the chiral expansion of the Eta -> 3Pi amplitude in the physical regio
n has proved problematic\, as it fails to reproduce the recent precise mea
surements of the Dalitz plot parameters. In order to circumvent this probl
em\, it was proposed to combine the chiral expansion\, used in an unphysic
al region\, together with the dispersive formalism of Khuri and Treiman.
We discuss here the possibility of extending this formalism\, which so far
accounts for only elastic pi-pi rescattering\, in order to further accoun
t for the effects of both inelastic pi-pi rescattering and eta-pi rescatte
ring. In the 1 GeV region of the dispersive integrands\, in particular\, t
hese effects are enhanced by the f_0 as well as the a_0 resonances. The e
ffect of the isospin violating K^+-K^0 mass difference\, influenced by the
se resonances\, is then also accounted for in the dispersive integrals.\n\
nhttps://agenda.infn.it/event/7897/contributions/70572/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70572/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral three-nucleon forces up to N4LO
DTSTART;VALUE=DATE-TIME:20150630T130000Z
DTEND;VALUE=DATE-TIME:20150630T131500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70571@agenda.infn.it
DESCRIPTION:Speakers: Hermann Krebs (Ruhr University Bochum)\nThree-nucleo
n forces play very important role in few and many-body simulations of nucl
ei/nuclear reactions at low energy. Knowledge of their precise form might
lead to resolution of long standing puzzles in few-nucleon physics (e.g. A
y-puzzle in elastic nucleon deuteron scattering). Chiral effective field
theory provides a systematically improvable tool for their calculation. B
y now three-nucleon forces have been calculated up to N3LO (partly up to N
4LO) in chiral expansion. In my talk I will discuss the current status of
their construction and their ongoing implementation in few-body calculati
ons\n\nhttps://agenda.infn.it/event/7897/contributions/70571/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70571/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The pi^0 -> gamma gamma^* decay rate and form factor
DTSTART;VALUE=DATE-TIME:20150702T153000Z
DTEND;VALUE=DATE-TIME:20150702T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70570@agenda.infn.it
DESCRIPTION:Speakers: Aron Bernstein (Massachusetts Institute of Technolog
y\, Cambridge)\nThe pi^0 rightarrow gamma gamma decay rate is dominated by
the QCD axial anomaly that is increased by approx 4.5% +- 1.0% by the mix
ing of the pi^0 wave function with the eta\, eta^' mesons. This relatively
large isospin breaking effect is proportional to the mass difference of
the up and down quarks. It has been calculated in Chiral Perturbation Theo
ry (ChPT) by three slightly different methods with good agreement between
them. This is a solid QCD prediction\; the error is due to the uncertainty
due to our knowledge of the low energy constants of ChPT and not by highe
r order terms.The accuracy of the present experiments are significantly le
ss than the theoretical prediction and represents a significant experiment
al challenge. A summary of the three three experimental methods to perform
this measurement and current efforts to improve them will be briefly revi
ewed with emphasis on one by the COMPASS collaboration at CERN. \n\nFor th
e pi^0 -> gamma gamma* decay the form factor can be written as F(Q^2) = F(
0)(1 -R(pi^0)^2 Q^2/6 +...) at low Q^2. This suggests a possible way to m
easure the size ("anomaly radius") of the pi^0 meson which does not have a
charge or magnetic radius. Using the latest\, most accurate\, calculated
value of the slope parameter obtained from a dispersive analysis of the pi
on transition form factor\, this RMS radius is 5% smaller than the pi^pm
electric radius. Using vector dominance these radii are expected to be equ
al. However this similarity\, and the difference between these values\, ca
lls for a careful theoretical and experimental examination of this fundame
ntal quantity. Clearly the charge and "anomaly" radii correspond to the ex
pectation values of different operations. A comparison of the scalar and e
lectromagnetic radii of the pion and proton with some interesting (puzzlin
g?) differences will be presented.\n\nhttps://agenda.infn.it/event/7897/co
ntributions/70570/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70570/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Understanding pion through QCD
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70569@agenda.infn.it
DESCRIPTION:Speakers: Khepani Raya (University of Michoacan\, Morelia)\nWe
present recent advances in the study of the Pion structure through Dyson-
Schwinger Equations\, the equations of motion of QCD. In particular\, we d
iscuss the neutral pion to two photons transition form factor\, a problem
which involves careful parametrizations of the quark propagator and Bethe-
Salpeter Amplitudes. This calculation is relevant for future experiments t
o be conducted at Belle II.\n\nhttps://agenda.infn.it/event/7897/contribut
ions/70569/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70569/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A dispersive treatment of K_{l4} decays
DTSTART;VALUE=DATE-TIME:20150629T142000Z
DTEND;VALUE=DATE-TIME:20150629T144000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70568@agenda.infn.it
DESCRIPTION:Speakers: Peter Stoffer (HISKP\, University of Bonn)\nK_{l4} d
ecays have several features of interest: they allow an accurate measuremen
t of ππ-scattering lengths\; the decay is the best source for the determ
ination of some low-energy constants of chiral perturbation theory (χPT)\
; one form factor of the decay is connected to the chiral anomaly. We pres
ent the final results of our dispersive analysis of K_{l4} decays\, which
provides a resummation of ππ- and Kπ-rescattering effects [1\,2]. The f
ree parameters of the dispersion relation are fitted to the data of the hi
gh-statistics experiments E865 [3\,4] and NA48/2 [5\,6]. The data input is
corrected for additional isospin-breaking effects\, which were not taken
into account in the experimental analyses [7]. By matching to χPT at NLO
and NNLO\, we determine the low-energy constants L1r\, L2r\, and L3r. Rece
ntly published data [6] from NA48/2 allow even a determination of L9r. In
contrast to a pure chiral treatment\, the dispersion relation describes th
e observed curvature of one of the K_{l4} form factors\, which we understa
nd as an effect of rescattering beyond NNLO.\n\nReferences\n1. G. Colangel
o\, E. Passemar\, and P. Stoffer\, arXiv:1501.05627 [hep-ph].\n2. P. Stoff
er\, PhD thesis\, University of Bern\, 2014\, arXiv:1412.5171 [hep-ph].\n3
. S. Pislak et al. (BNL-E865 Collaboration)\, Phys. Rev. Lett. 87\, 221801
(2001)\,[Erratum-ibid. 105\, 019901 (2010)]\, [arXiv:hep-ex/0106071].\n4.
S. Pislak et al. (BNL-E865 Collaboration)\, Phys. Rev. D67\, 072004 (2003
)\, [Erratum-ibid. D81\, 119903 (2010)]\, [arXiv:hep-ex/0301040].\n5. J. B
atley et al. (NA48-2 Collaboration)\, Eur. Phys. J. C70\, 635 (2010).\n6.
J. Batley et al. (NA48/2 Collaboration)\, Phys. Lett. B715\, 105 (2012)\,
[arXiv:1206.7065 [hep-ex]]\, [Addendum-ibid. B740\, 364 (2015)].\n7. P. St
offer\, Eur. Phys. J. C74\, 2749 (2014)\, [arXiv:1312.2066 [hep-ph]].\n\nh
ttps://agenda.infn.it/event/7897/contributions/70568/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70568/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Power counting of currents in effective field theory
DTSTART;VALUE=DATE-TIME:20150702T134000Z
DTEND;VALUE=DATE-TIME:20150702T135500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70567@agenda.infn.it
DESCRIPTION:Speakers: Manuel Pavon Valderrama (IPN Orsay)\nEffective field
theories are generic descriptions of low-energy phenomena for which a fun
damental theory is unknown or impractical to solve. The formulation of EFT
s is grounded on symmetries and power counting. While symmetries provide t
he connection with the underlying theory\, power counting -- how to order
the effective interactions from more to less relevant -- makes EFTs predic
tive and systematic. However power counting is in general not trivial. For
systems that are perturbative at low energies one can establish the count
ing using naive dimensional analysis (NDA)\, which states that the dimensi
onful couplings of EFT scale as powers of M. But when low energy physics i
s non-perturbative\, the choice of a counting that is theoretically consis
tent and phenomenologically acceptable is a much more involved task. For n
uclear physics\, which is non-perturbative (e.g. the deuteron)\, NDA fails
. Yet we know now how to organize the counting\, though until recently onl
y in the two-body sector.\n\nIn this contribution we explain how to extend
power counting to reactions involving an external probe -- such as a phot
on\, electron or neutrino -- and two nucleons. We use renormalization grou
p analysis (RGA) as the tool to determine the size of nuclear two-body cur
rents. The findings we made are compatible with well-known observations in
the previous literature\, for instance\, the necessity of a two-body curr
ent in radiative neutron capture or that deuteron form factors can be expl
ained to good accuracy without contact two-body currents. In the pionless
case we find that there arr important departures from NDA in a few reactio
ns\, particularly those involving the 1S_0 singlet channel\, indicating th
at many previous EFT calculations could be improved by taking these change
s in consideration.\n\nhttps://agenda.infn.it/event/7897/contributions/705
67/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70567/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Muon capture on the deuteron
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70566@agenda.infn.it
DESCRIPTION:Speakers: AlaaEldeen Elmeshenb (Jagiellonian University\, Krak
ow)\nThe study of few-nucleon system is interesting and important. It give
s a microscopic description of complex systems within the framework of mod
ern concepts of nucleon-nucleon and many-body interactions. Using the muon
capture process is an ideal tool to study few-nucleon systems. In this wo
rk we plan to investigate the µ− + d → ν_µ + n + n capture reaction
. This reaction is interesting for several reasons. First of all\, it offe
rs a testing ground for the nuclear wave functions\, which for any nucleon
-nucleon (NN) forces can be constructed for such light systems with great
accuracy. This reaction\, is treated as the decay of the corresponding muo
nic atom\, with the muon initially on the lowest K shell. The muon binding
energy in this atom can be safely neglected and in the initial state we d
eal essentially with the deuteron and muon at rest. The general formalism
for dealing with electroweak reactions on the deuteron will be presented.
We will concentrate on the nuclear matrix elements of the corresponding we
ak current operator calculated in the momentum space within partial wave d
ecomposition scheme. In the current operator apart from the relatively wel
l known single nucleon contributions\, the two-nucleon parts (generated by
various meson exchange) play an important role. Their details are not wel
l known and several models should be considered [1]. We will employ variou
s models of NN and 3N forces\, such as the Bonn B [2] or chiral NNLO poten
tials [3]. Additionally\, we will be able to use for the ﬁrst time the s
o-called ”improved” chiral nucleon-nucleon potentials from the Bochum-
Bonn group [4] for the µ− + d → ν_µ + n + n capture reaction\, we w
ill show our predictions for all the available ﬁve orders of the chiral
expansion and for all the ﬁve regulators at each order. The estimate of
the total decay rates and diﬀerential capture rates as a function of the
neutron momentum will be presented in a comparison with the experimental
data. The decay rates will be investigated in the energy spectrum of the o
mitted neutrinos. Our results with the single nucleon currents look alread
y very promising and we hope for the improvement in the description of the
experimental data\, when dominant two-nucleon current operators are inclu
ded in our framework.\n\nReferences\n1. L. Marcucci et al.\, Phys. Rev. C8
3\, 014002 (2011).\n2. R. Machleidt\, Adv. Nucl. Phys. 19 (1989) 189.\n3.
E. Epelbaum\, Prog. Part. Nucl. Phys. 57\, 654 (2006).\n4. E. Epelbaum\, H
. Krebs\, U.-G. Meißner\, arXiv:1412.0142 [nucl-th] (2014).\n\nhttps://ag
enda.infn.it/event/7897/contributions/70566/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70566/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extending the baryon ChPT beyond the low-energy region
DTSTART;VALUE=DATE-TIME:20150630T153000Z
DTEND;VALUE=DATE-TIME:20150630T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70565@agenda.infn.it
DESCRIPTION:Speakers: Jambul Gegelia (Forschungszentrum Jülich)\nWe sugge
st an extension of the one-nucleon sector of baryon chiral perturbation th
eory beyond the low-energy region. Applicability of the proposed approach
for higher energies is restricted to small scattering angles\, i.e. the ki
nematical region where the quark structure of hadrons cannot be resolved.
The main idea is to re-arrange the low-energy effective Lagrangian accordi
ng to a new power counting and for loop diagrams exploit the freedom of th
e choice of the renormalization condition. We generalize the extended on-m
ass-shell scheme for the one-nucleon sector of the baryon chiral perturbat
ion theory by choosing a sliding scale\, i.e. expand the physical amplitud
es around kinematical points far beyond the threshold. This requires an in
troduction of complex-valued renormalized coupling constants which can be
either extracted from experimental data\, or calculated using the renormal
ization group evolution of coupling constants fixed in threshold region.\n
\nhttps://agenda.infn.it/event/7897/contributions/70565/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70565/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral perturbation theory of hyperfine splitting in muonic hydrog
en
DTSTART;VALUE=DATE-TIME:20150629T132000Z
DTEND;VALUE=DATE-TIME:20150629T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70564@agenda.infn.it
DESCRIPTION:Speakers: Franziska Hagelstein (Johannes Gutenberg University\
, Mainz)\nWe present the predictions of baryon chiral perturbation theory
(BChPT) for the proton polarizability contribution to the 2P −2S Lamb sh
ift and the 2S hyperfine splitting (HFS) in muonic hydrogen\, and compare
them to the results of dispersive calculations. The spin-dependent part of
the forward doubly-virtual Compton scattering amplitude (S1\,2) contribut
es to the 2S HFS\, whereas the spin-independent part of the amplitude (T1\
,2) to the 2P −2S Lamb shift. All invariant amplitudes are related to ph
otoabsorption cross sections by dispersion sum rules\, however the amplitu
de T1 requires a subtracted dispersion relation. Therefore\, in contrast t
o the HFS\, the polarizability contribution to the Lamb shift is not deter
mined by the empirical information (on structure functions) alone and requ
ires a rigorous theoretical input. Such an input has been provided by rece
nt ChPT calculations\, cf. [1] and references therein. We extend the calcu
lation of Ref. [1] to the HFS\, where the reliability of both ChPT and dis
persive calculations is put to the\ntest.\n\nReferences\n1. J. M. Alarcon\
, V. Lensky\, V. Pascalutsa\, Eur. Phys. J. C74 (2014) 2852.\n\nhttps://ag
enda.infn.it/event/7897/contributions/70564/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70564/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The H-dibaryon in two flavor lattice QCD
DTSTART;VALUE=DATE-TIME:20150702T155000Z
DTEND;VALUE=DATE-TIME:20150702T161000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70563@agenda.infn.it
DESCRIPTION:Speakers: Parikshit Junnarkar (Helmholtz Institut\, Mainz)\nWe
present preliminary results from a lattice QCD calculation of the H-dibar
yon using two flavors ofO(a) improved Wilson fermions. We employ six quark
interpolating operators with the appropriate quantum numbers of the H-dib
aryon and also explore its couplings to two-baryon channels. We apply two
smearings to improve the overlap to the ground state\, which is obtained b
y solving a generalised eigenvalue problem. The inclusion of multi-partic
le operators enables the application of Luescher's finite volume formalism
to obtain information on the nature of the infinite volume interaction of
two particles. Further\, the correlators are projected to three moving fr
ames enabling the isolation of the infinite volume bound/scattering state.
Preliminary results on pion mass of 1GeV indicate the H-dibaryon is bound
in the infinite volume. Results at a lower pion mass of 451 MeV will also
be presented.\n\nhttps://agenda.infn.it/event/7897/contributions/70563/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70563/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Review of the Proton Size Puzzle
DTSTART;VALUE=DATE-TIME:20150629T123000Z
DTEND;VALUE=DATE-TIME:20150629T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70562@agenda.infn.it
DESCRIPTION:Speakers: Carl Carlson (College of William and Mary\, Williams
burg)\nThe proton charge radius puzzle exists because the proton charge ra
dius appears different when measured with electrons than when measured wit
h muons. "Ordinary" explanations include problems with the extrapolations
or theoretical corrections involved in the measurements\, and "exotic" exp
lanations include such beyond the standard model ideas as a breakdown of e
lectron-muon universality. We will discuss possibilities in both categori
es.\n\nhttps://agenda.infn.it/event/7897/contributions/70562/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70562/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Studies of the decay K+ to pi+ pi0 e+ e- at NA48
DTSTART;VALUE=DATE-TIME:20150629T130000Z
DTEND;VALUE=DATE-TIME:20150629T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70561@agenda.infn.it
DESCRIPTION:Speakers: Jacopo Pinzino (INFN-Pisa)\nWe report the first obse
rvation of the very rare decay K+- -> pi+- pi0 e+ e- by the NA48/2 experim
ent. From a clean sample of almost 2000 reconstructed signal events\, we h
ave determined the branching fraction with high precision and measured the
e+ e- invariant mass distribution\, which allows to differentiate between
different decay models.\n\nhttps://agenda.infn.it/event/7897/contribution
s/70561/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70561/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Studies of the Ke4 decay at NA48
DTSTART;VALUE=DATE-TIME:20150629T132000Z
DTEND;VALUE=DATE-TIME:20150629T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70560@agenda.infn.it
DESCRIPTION:Speakers: Michal Zamkovsky (IPNP\, Charles University\, Prague
)\nThe NA48/2 experiment has recently published a detailed study of the Ke
4 decay mode K —> pi0 pi0 e nu based on 65000 candidates with a low 1% b
ackground contamination. The achieved experimental precision brings eviden
ce for isospin breaking mass effects and final state pi pi scattering. The
oretical calculations will have to face a new precision challenge when usi
ng such improved inputs to extract for example low energy constants of Chi
ral Perturbation Theory.\n\nhttps://agenda.infn.it/event/7897/contribution
s/70560/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70560/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electric dipole moments\, new physics\, and QCD
DTSTART;VALUE=DATE-TIME:20150629T095000Z
DTEND;VALUE=DATE-TIME:20150629T103000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70559@agenda.infn.it
DESCRIPTION:Speakers: Vincenzo Cirigliano (Los Alamos National Laboratory)
\nElectric Dipole Moments (EDMs) of leptons\, nucleons\, atoms\, and mol
ecules are great probes of new sources of CP violation originating from p
hysics beyond the Standard Model (BSM). In this talk I will discuss the
central role that QCD and chiral dynamics play in the interpretation of
current experimental searches. After an overview of the physics reach of
various EDM searches\, I will briefly review the chiral effective theory
framework needed for the interpretation of hadronic and nuclear EDM search
es. I will then present recent work towards the computation of the BSM-
induced neutron and proton EDM using lattice QCD.\n\nhttps://agenda.infn.
it/event/7897/contributions/70559/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70559/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Probes for fundamental QCD symmetries and a dark gauge boson via l
ight meson decays
DTSTART;VALUE=DATE-TIME:20150629T103000Z
DTEND;VALUE=DATE-TIME:20150629T111000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70558@agenda.infn.it
DESCRIPTION:Speakers: Liping Gan (University of North Carolina\, Wilmingto
n)\nLight Meson decays provide a unique laboratory to probe fundamental QC
D symmetries and to search for new physics beyond the Standard Model. A co
mprehensive Primakoff experimental program at Jefferson Laboratory (Jlab)
is aimed at gathering high precision measurements on the two-photon decay
widths and transition form factors at low Q2 of π0\, η and η′ via the
Primakoff effect. Completed experiments on the π0 radiative decay width
at Jlab 6 GeV\, and planned measurements of η and η′ at Jlab 12 GeV wi
ll provide sensitive probes to test the chiral anomaly and to study the or
igin and dynamics of chiral symmetry breaking in QCD confinement. On the o
ther hand\, a recently developed Jlab Eta Factory (JEF) experiment will me
asure various η decays. The experimental approach\, which combines a stat
e of the art PbWO4 crystal calorimeter\, a 12 GeV tagged photon beam\, and
recoil particle measurement\, will reduce the background by almost two or
ders of magnitude in the rare neutral modes compared to other competitors
in the world. Reduction of the uncertainty on the light quark mass ratio w
ill be achieved by increasing the world datasets for both the charged and
neutral η → 3π Dalitz distributions by a factor of ∼ 3 while control
ling systematic uncertainties with relatively flat detection efficiencies
over the phase space due to significantly boosted η’s. A low-background
measurement of the rare decay η → π0γγ will provide a clean\, rare
window into O(p6) in chiral perturbation theory\, while offering a unique
opportunity to search for a dark leptophobic gauge boson (B) in the 140-55
0 MeV mass range\, with sensitivity to the baryonic fine structure constan
t αB as low as 10−7. The SM forbidden decays\, such as η → 3γ and
η → 2π0 γ\, will allow the best direct constraints on new C violating
\, P conserving reactions. A overview of these experimental activities and
their physics impacts will be presented.\n\nhttps://agenda.infn.it/event/
7897/contributions/70558/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70558/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Latest results on few-body physics from HIγS
DTSTART;VALUE=DATE-TIME:20150701T091000Z
DTEND;VALUE=DATE-TIME:20150701T095000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70557@agenda.infn.it
DESCRIPTION:Speakers: Haiyan Gao (Duke University\, Durham)\nAn important
goal in modern nuclear physics is to understand how one can describe the s
tructure of nuclei and nuclear forces from first principles of quantum chr
omodynamics (QCD)\, the fundamental theory describing the strong interacti
on. Few-nucleon systems provide important testing grounds for state-of-the
-art few-body calculations\, calculations based on effective field theorie
s\, and more recently predictions from lattice QCD. As such they are impor
tant laboratories to investigate nucleon-nucleon interaction and nuclear f
orces\, and connect them to QCD. With the availability of high-intensity\,
near monochromatic\, highly (linearly or circularly) polarized gamma rays
from The High Intensity Gamma ray Source (HIγS) facility at the Duke Uni
versity Free Electron Laser Laboratory\, new few-body experiments utilizin
g these unique features of the beam and polarized targets have been carrie
d out or are underway. In this talk\, I will discuss these experiments and
present latest results on few-body physics from HIγS.\n\nhttps://agenda.
infn.it/event/7897/contributions/70557/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70557/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effective field theories and lattice QCD
DTSTART;VALUE=DATE-TIME:20150629T080500Z
DTEND;VALUE=DATE-TIME:20150629T084500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70556@agenda.infn.it
DESCRIPTION:Speakers: Claude Bernard (Washington University\, Saint Louis)
\nI describe some of the many connections between lattice QCD and effectiv
e field theories\, focusing in particular on chiral effective theory\, but
also touching upon Symanzik effective theory and heavy quark effective th
eory. Ifirst discuss the ways in which effective theories have enabled and
supported lattice QCD calculations. Particular attention is paid to the i
nclusion of discretization errors\, for a variety of lattice QCD actions\,
into chiral effective theory. Several other examples of the usefulness of
chiral perturbation theory\, including the encoding of partial quenching
and of twisted boundary conditions\, are also described. In the second par
t of the talk\, I turn to results from lattice QCD for the low energy cons
tants of the two- and three-flavor chiral theories. I concentrate here on
mesonic quantities\, but a few results for nucleons are also mentioned. Fi
nally I discuss some recent preliminary lattice QCD calculations by the MI
LC Collaboration relating to the three-flavor chiral limit.\n\nhttps://age
nda.infn.it/event/7897/contributions/70556/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70556/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theoretical aspects of Chiral Dynamics
DTSTART;VALUE=DATE-TIME:20150629T072500Z
DTEND;VALUE=DATE-TIME:20150629T080500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70555@agenda.infn.it
DESCRIPTION:Speakers: Heinrich Leutwyler (University of Bern)\nMany of the
quantities of interest at the precision frontier in particle physics requ
ire a good understanding of the low energy properties of the strong intera
ction. I intend to focus on the fact that applications of effective field
theory methods usually involve two aspects: dependence on the quark masses
and dependence on the momenta. On the one hand\, I will review some of th
e work done in dispersion theory\, which led to an improved understanding
of the momentum dependence. On the other hand\, some of the results gained
by means of lattice methods concerning the quark mass dependence will be
discussed. As an illustrative example\, I plan to critically examine recen
t work on the mass difference between proton and neutron.\n\nhttps://agend
a.infn.it/event/7897/contributions/70555/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70555/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The meson spectroscopy program with CLAS12 at Jefferson Laboratory
DTSTART;VALUE=DATE-TIME:20150630T153000Z
DTEND;VALUE=DATE-TIME:20150630T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70554@agenda.infn.it
DESCRIPTION:Speakers: Alessandro Rizzo (INFN-Roma2)\nThe study of the hadr
onic spectrum is one of the most powerful tools to investigate the mechani
sm at the basis of quark confinement within hadrons. A precise determinati
on of the spectrum allows not only to asses the properties of the hadrons
in their fundamental and excited states\, but also to investigate the exis
tence of states resulting from alternative configurations of quarks and gl
uons configurations\, such as the glue-balls\, hybrid mesons and many-quar
ks configurations. The mesonic part of the spectrum can play a central rol
e in this investigation because several of the hybrid mesons are supposed
to have different quantum numbers with respect to standard q¯q states\, d
ue to the presence of explicit gluonic degrees of freedom. The hybrid meso
ns are expected to decay into multi-particles final states [1]\, requiring
high performances in terms of rate capability\, resolution and acceptance
for their detection. New-generation experiments are planned at Jefferson
Laboratory (JLAB) for which an unprecedented statistics of events with ful
ly reconstructed kinematics for large multiplicity decays will be availabl
e. A wide scientific program that will start in 2016 has been deployed for
meson spectrum investigation with the CLAS12 apparatus in Hall B at energ
ies up to 11 GeV. A key role in such program is played by the Forward Tagg
er [2]\, which will allow to extend the study of meson electro-production
to very low Q2\, in a quasi-real photo production kinematical region\, whe
re the production of hybrid mesons is expected to be favorite. The analysi
s required to extract the signal from hybrid states should go beyond the s
tandard Partial Wave analysis techniques and a new analysis framework is b
eing set up through the Haspect Network. The Haspect Network gather people
involved into theoretical and experimental hadronic physics all over the
world\, to investigate and propose new analysis models (such as the Szczep
aniak-Pennington model [3]) and new statistical techniques to unfold signa
l and background. The new analysis framework is being tested using the exi
sting CLAS data and results are projected to the CLAS12 performances\, sho
wing that the quest for hybrid exotic mesons is at reach.\n\nReferences\n1
. A. Szczepaniak\, Phys.Rev. D 59 (1999)\, p. 034016.\n2. The CLAS collabo
ration\, https://www.jlab.org/Hall-B/clas12-web/docs/ft-tdr.2.0.pdf\n3 A.
Szczepaniak and M.R. Pennington\, arXiv:1403.5782v1 [hep-ph] 23 Mar 2014\n
\nhttps://agenda.infn.it/event/7897/contributions/70554/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70554/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Antinucleon-nucleon interaction and the related hadron physics
DTSTART;VALUE=DATE-TIME:20150630T153000Z
DTEND;VALUE=DATE-TIME:20150630T154500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70553@agenda.infn.it
DESCRIPTION:Speakers: Xian-Wei Kang (IAS and IKP\, Forschungszentrum Jüli
ch)\nThe recent development of the antinucleon-nucleon (N-bar N) interacti
on in chiral effective\nfield theory [1] will be reported and the phenomen
ological meson-exchange models (taking Julich model as an example) will be
mentioned as well. With such potentials and the distorted-wave Born appro
ximation\, we examine the influence of the antiproton-proton (p-bar p) int
eraction on the mass spectrum in various reactions containing the antip p
pair\, e.g.\, J/ψ → γ¯pp\, ω¯pp\, π0¯pp and e+e−↔ p-bar p. It
turns out that the low-energy mass spectra up to excess energy of 100 MeV
for all the mentioned processes can be described by our treatment of the
final or initial state (p-bar p) interactions. In J/ψ → γ p-bar p the
quite prominent peak near p-bar p threshold is observed in BES experiment\
, and to describe it\, a bound state in isospin-1 1S0 is needed in our cal
culation [2]. The electromagnetic form factors of the proton in the time-l
ike region are also predicted [3]. The role of N-bar N intermediate states
played in the ractions e+e−→ multi-pions will be also discussed\, whi
ch concerns for the dip structure observed around N-bar N threshold in the
experiments.\n\nReferences\n1. X.-W. Kang\, J. Haidenbauer and U. G. Mei
ßner\, JHEP 1402\, 113 (2014).\n2. X.-W. Kang\, J. Haidenbauer and U. G.
Meißner\, arXiv:1502.00880 [nucl-th].\n3. J. Haidenbauer\, X.-W. Kang and
U.-G. Meißner\, Nucl. Phys. A 929\, 102 (2014).\n\nhttps://agenda.infn.i
t/event/7897/contributions/70553/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70553/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Eta and eta' physics at BESIII
DTSTART;VALUE=DATE-TIME:20150630T123000Z
DTEND;VALUE=DATE-TIME:20150630T130000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70552@agenda.infn.it
DESCRIPTION:Speakers: Shuangshi Fang (Institute of High Energy Physics\, B
ejing)\nThe BESIII Experiment at the Beijing Electron Positron Collider (B
EPCII) has accumulated the world's largest samples of e+e- collisions in t
he tau-charm region. From a sample of 1.3 billions J/psi decays\, BESIII
has produced many new results in the decays of eta and eta'. This talk wi
ll review the current status of these analyses\, especially on the Dalitz
plot of eta/eta'\, observations of eta'-->4pi\, gamma gamma pi0 and gamma
e+e-.\n\nhttps://agenda.infn.it/event/7897/contributions/70552/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70552/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral dynamics in the gamma p --> p pi0 reaction
DTSTART;VALUE=DATE-TIME:20150629T153000Z
DTEND;VALUE=DATE-TIME:20150629T155000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70551@agenda.infn.it
DESCRIPTION:Speakers: Astrid Hiller Blin (IFIC\, University of Valencia)\n
We investigate the neutral pion photoproduction on the proton near thresho
ld in covariant chiral perturbation theory with the explicit inclusion of
Delta degrees of freedom. This channel is specially sensitive to chiral dy
namics and the advent of very precise data from the Mainz microtron has sh
own the limits of the convergence of the chiral series for both the heavy
baryon and the covariant approaches. We show that the inclusion of the Del
ta resonance substantially improves the convergence leading to a good agre
ement with data for a wider range of energies.\n\ne-Print: arXiv:1412.4083
[hep-ph]\n\nhttps://agenda.infn.it/event/7897/contributions/70551/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70551/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Recoil corrections in antikaon-deuteron scattering
DTSTART;VALUE=DATE-TIME:20150629T160000Z
DTEND;VALUE=DATE-TIME:20150629T161500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70550@agenda.infn.it
DESCRIPTION:Speakers: Maxim Mai (HISKP\, University of Bonn)\nThe recoil r
etardation effect in the K¯d scattering length is studied. Using the nonr
elativistic effective field theory approach\, it is demonstrated that a sy
stematic perturbative expansion of the recoil corrections in the parameter
ξ=MK/mN is possible in spite of the fact that K-d scattering at low ener
gies is inherently nonperturbative due to the large values of the K¯N sca
ttering lengths. \n\nThe first-order correction to the K¯d scattering len
gth due to single insertion of the retardation term in the multiple-scatte
ring series is calculated. The recoil effect turns out to be reasonably sm
all even at the physical value of MK/mN approx 0.5. In the talk I will pre
sent these results as well as our more recent estimation of higher order c
orrections and the possibility to resum the recoil corrections to all orde
rs.\n\nhttps://agenda.infn.it/event/7897/contributions/70550/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70550/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Compton scattering from 3He and 4He using an active target
DTSTART;VALUE=DATE-TIME:20150702T152000Z
DTEND;VALUE=DATE-TIME:20150702T153500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70549@agenda.infn.it
DESCRIPTION:Speakers: John Annand (University of Glasgow)\nAn experiment t
o measure the differential cross section for Compton scattering from 3He a
nd 4He at the MAMI tagged photon facility in Mainz is described. The objec
tive is to measure the isoscalar nucleon electromagnetic polarisabilities
and thus access the neutron polarisabilities. The experiment will use a hi
gh-pressure gas-scintillator active target to measure recoiling He ions in
coincidence with the scattered photon\, detected in the Crystal Ball and
TAPS 4-Pi electromagnetic calorimeter. Recent work to develop a chiral eff
ective field theory treatment of Compton scattering on 3He is also describ
ed\, and the relative merits of using 2H\, 3He or 4He as "neutron targets"
discussed in the light of recent experiments on 2H.\n\nhttps://agenda.inf
n.it/event/7897/contributions/70549/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70549/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The proton spin-dependent structure function\, g2\, at low Q2
DTSTART;VALUE=DATE-TIME:20150702T130000Z
DTEND;VALUE=DATE-TIME:20150702T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70548@agenda.infn.it
DESCRIPTION:Speakers: Ryan Zielinski (University of New Hampshire\, Dover)
\nThe Jefferson Laboratory accelerator has been used to great effect in th
e study of the polarized structure of nucleons. Measurements of the spin-d
ependent structure functions have been proven to be powerful tools in test
ing the validity of effective theories of Quantum Chromodynamics. While th
e neutron spin structure functions\, g1n and g2n \, and the longitudinal p
roton spin structure function\, g1p\, have been measured over a wide kinem
atic range\, the second proton spin structure function\, g2p\, has not. Th
is talk will present the E08-027 (g2p) experiment\, which was an inclusive
measurement of g2p in the resonance region at Jefferson Lab's Hall A. Thi
s is the first measurement of g2p covering 0.02 GeV2 \n\nhttps://agenda.in
fn.it/event/7897/contributions/70548/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70548/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Impact of the Delta (1232) resonance in neutral pion photoproducti
on in chiral perturbation theory.
DTSTART;VALUE=DATE-TIME:20150629T155000Z
DTEND;VALUE=DATE-TIME:20150629T161000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70547@agenda.infn.it
DESCRIPTION:Speakers: Lloyd Cawthorne (University of Manchester)\nIn this
talk we will discuss the reaction p + γ → p + π0 and how it has been d
escribed using Chiral Perturbation Theory (χPT).\n\nSince the early 1990s
χPT has been applied to pion photoproduction. The first study was that o
f Bernard et al. [1\,2]\, detailing a O(p3) relativistic approach to descr
ibe the data from Mainz [3] and Saclay [4] from threshold\, Eγ ≈ 145 Me
V\, to Eγ ≈ 160 MeV. In 1996 and 2001 the same authors revisited this p
henomenon in O(p4) heavy baryon χPT [5\,6]. They improved on previous res
ults by fitting to data from threshold to Eγ ≈ 165 MeV. There has been
a resurgence of interest in this topic following the publication of the re
sults from the A2 and CB-TAPS collaborations at the Mainz Microtron (MAMI)
[7]. This data has reached unprecedented levels of accuracy from the thre
shold region through to the first excited hadronic state\, the ∆(1232).
This data was analyzed by Fernandez-Ramirez et al. [8] using rel. χPT and
HBχPT. They concluded that for energies above Eγ ≈ 170 MeV both the t
heories fail. All of the above studies acknowledge that the ∆(1232) is i
mportant but do not include it in their work. It was incorporated into a O
(p3) EOMS covariant theory late last year by Blin et al. [9]. Their analys
is showed how including the resonance improves the fit. Another aspect hig
hlighted by Fernandez-Ramirez et al. [10] is that calculations often limit
the angular momentum to P-waves\, when it is not fully understood if the
interference produced from D-wave states (or higher) are negligible. In ou
r discussion\, we will detail both the relativistic and the heavy baryon a
pproach.\n\nFurthermore\, we will show the effects of including the ∆(12
32)\, and how this improves theoretical descriptions of this phenomenon. F
inally\, we will discuss the consequences of truncating the angular-moment
um to P-waves\, compared to including D-waves and higher.\n\nReferences\n1
. V. Bernard et al\, Nucl. Phys. B 383\, 442 (1992).\n2. V. Bernard et al\
, Phys. Reps. 246\, 315 (1994).\n3. E. Mazzucato et al\, Phys. Rev. Lett.
57\, 3144 (1986).\n4. R. Beck et al\, Phys. Rev. Lett. 65\, 1841 (1990).\n
5. V. Bernard et al\, Z. Phys. C 70\, 483 (1996).\n6. V. Bernard et al\, E
ur. Phys. J. A 11\, 209 (2001).\n7. D. Hornidge et al\, Phys. Rev. Lett. 1
11\, 062004 (2013).\n8. C. Fernandez-Ramirez et al\, EPJ Web Conf. 73\, 04
007 (2014).\n9. A. Blin et al\, arxiv:1412.4083.\n10. C. Fernandez-Ramirez
et al\, Phys. Rev. C 80\, 065201 (2009).\n\nhttps://agenda.infn.it/event/
7897/contributions/70547/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70547/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dispersion relation for hadronic light-by-light scattering and the
muon (g-2)
DTSTART;VALUE=DATE-TIME:20150702T132000Z
DTEND;VALUE=DATE-TIME:20150702T134000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70546@agenda.infn.it
DESCRIPTION:Speakers: Peter Stoffer (HISKP\, University of Bonn)\nThe anom
alous magnetic moment of the muon (g −2)µ has been measured and compute
d to very high precision of about 0.5 ppm. For more than a decade\, a disc
repancy has persisted between experiment and Standard Model prediction\, n
ow of about 3σ. The main uncertainty of the theory prediction is due to s
trong interaction effects. With the expected improvement of the input for
hadronic vacuum polarisation\, in a few years the subleading hadronic ligh
t-by-light (HLbL) contribution will dominate the theory error. While some
constraints from QCD exist\, the calculation of the HLbL contribution to t
he (g − 2)µ is plagued by a substantial model dependence. In this talk\
, I will present a dispersive approach to HLbL scattering\, based on the f
undamental principles of unitarity and analyticity [1] We have derived a L
orentz decomposition of the HLbL tensor that is fully gauge-invariant and
crossing symmetric [2\,3]. The scalar coefficient functions of this tensor
decomposition are free of kinematic singularities and zeros and fulfil Ma
ndelstam’s double-dispersive representation. The dispersive formalism de
fines unambiguously and in a model-independent way both the pion-pole and
the pion-loop contribution. Two-pion rescattering effects are included in
a partial-wave picture. Our dispersive formalism shows a path towards a da
ta-driven determination of the HLbL contribution to the (g − 2)µ [4].\n
\nReferences\n1. G. Colangelo\, M. Hoferichter\, M. Procura\, and P. Stoff
er\, JHEP 1409\, 091 (2014)\,[arXiv:1402.7081 [hep-ph]].\n2. G. Colangelo\
, M. Hoferichter\, M. Procura\, and P. Stoffer\, in preparation.\n3. P. St
offer\, PhD thesis\, University of Bern\, 2014\, arXiv:1412.5171 [hep-ph].
\n4. G. Colangelo\, M. Hoferichter\, B. Kubis\, M. Procura\, and P. Stoffe
r\, Phys. Lett. B738\, 6 (2014)\, [arXiv:1408.2517 [hep-ph]].\n\nhttps://a
genda.infn.it/event/7897/contributions/70546/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70546/
END:VEVENT
BEGIN:VEVENT
SUMMARY:*Leading Talk* Evidence that the Lambda(1405) is a molecular antik
aon-nucleon bound state.
DTSTART;VALUE=DATE-TIME:20150702T142000Z
DTEND;VALUE=DATE-TIME:20150702T145000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70545@agenda.infn.it
DESCRIPTION:Speakers: Waseem Kamleh (University of Adelaide)\nWe present l
attice QCD results showing that the strange magnetic form factor of the La
mbda(1405) vanishes\, signaling the formation of an antikaon–nucleon. To
gether with a Hamiltonian effective-field-theory model analysis of the lat
tice QCD energy levels\, this strongly suggests that the structure is domi
nated by a bound antikaon-nucleon component. This result clarifies that no
t all states occurring in nature can be described within a simple quark mo
del framework and points to the existence of exotic molecular meson-nucleo
n bound states.\n\nhttps://agenda.infn.it/event/7897/contributions/70545/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70545/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roper mass in chiral perturbation theory
DTSTART;VALUE=DATE-TIME:20150702T111000Z
DTEND;VALUE=DATE-TIME:20150702T123000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70544@agenda.infn.it
DESCRIPTION:Speakers: Xiu-Lei Ren (Beihang University/ IPN Orsay)\nUnderst
anding the nature of the Roper resonance is of particular interest. Its ma
ss\, for example\, shows a very unusual pattern: it is lower than the nega
tive parity state N(1535). Also\, the Roper is expected to play a role in
low energy observables due to its closeness to the nucleon and Delta(1232)
. \n\nWe report on a systematic study of the nucleon\, Delta(1232)\, and R
oper masses in heavy baryon chiral perturbation theory up to next-to-next-
to-leading order. For the first time\, the contributions due to the mixing
between the nucleon and the Roper allowed by chiral symmetry are taken in
to account. Recently\, several lattice QCD collaborations have reported so
me results on the Roper mass\, assuming this particle is always stable. A
chiral extrapolation of these data will also be shown as an application of
our results.\n\n* This work is done in collaboration with V. Bernard\, U.
van Kolck\, L.S. Geng\, and J. Meng.\n\nhttps://agenda.infn.it/event/7897
/contributions/70544/
LOCATION:Building E\, Polo Fibonacci\, Pisa Hall
URL:https://agenda.infn.it/event/7897/contributions/70544/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Octet baryon masses in covariant baryon chiral perturbation theory
up to O(p^4)
DTSTART;VALUE=DATE-TIME:20150630T151000Z
DTEND;VALUE=DATE-TIME:20150630T153000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70543@agenda.infn.it
DESCRIPTION:Speakers: Xiu-Lei Ren (Beihang University/IPN Orsay)\nWe repor
t on a recent study of the ground-state octet baryon masses and sigma term
s in the covariant baryon chiral perturbation theory (ChPT) with the exten
ded-on-mass-shell (EOMS) renormalization scheme up to next-to-next-to-next
-to-leading order (N3LO). To take into account lattice QCD artifacts\, the
finite-volume corrections (FVCs) and finite lattice spacing discretizatio
n effects are carefully examined.\n\nWe performed a simultaneous fit of al
l the publicly available n_f = 2+1 lattice QCD data from the PACS-CS\, LHP
C\, HSC\, QCDSF-UKQCD and NPLQCD collaborations and found that the N3LO EO
MS BChPT can describe the data reasonably well with chi^2/d.o.f. = 1.0. Ou
r study showed that the various lattice simulations are consistent with ea
ch other. Although the finite lattice spacing discretization effects up to
O(a^2) can be safely ignored\, but the finite volume corrections cannot e
ven for configurations with M_phi L>4. As an application\, we predicted th
e octet baryon sigma terms using the Feynman-Hellmann theorem. In particul
ar\, the pion- and strangeness-nucleon sigma terms are found to be sigma_{
pi N} = 55(1)(4) MeV and sigma_{sN} = 27(27)(4) MeV\, respectively.\n\nh
ttps://agenda.infn.it/event/7897/contributions/70543/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70543/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hyperons in nuclear matter studied in chiral EFT
DTSTART;VALUE=DATE-TIME:20150630T150000Z
DTEND;VALUE=DATE-TIME:20150630T151500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70542@agenda.infn.it
DESCRIPTION:Speakers: Johann Haidenbauer (IKP\, Forschungszentrum Juelich)
\nWe present results for the in-medium properties of a hyperon-nucleon (Y
N) interaction derived within chiral effective field theory (EFT) and fitt
ed to ΛN and ΣN scattering data. The single-particle potentials for the
Λ and Σ hyperons in nuclear matter are evaluated in a conventional G-mat
rix calculation\, and the Scheerbaum factor associated with the hyperon-nu
cleus spin-orbit interaction is computed [1]. We consider a leading-order
(LO) Y N interaction published in 2006 which accounts well for the bulk pr
operties of the ΛN and ΣN system [2]\, and our recent Y N potential deri
ved up to next-to-leading order (NLO) in chiral EFT which provides an exce
llent description of the available low-energy ΛN and ΣN cross sections a
nd the inelastic capture ratio at rest [3]. The predictions for the Λ sin
gle-particle potential are found to be in good qualitative agreement with
the empirical values inferred from hypernuclear data. A depth of about −
25 MeV is predicted by the NLO interaction and of about −36 MeV by the L
O potential. The Σ-nuclear potential turns out to be repulsive\, in agree
ment with phenomenological information\, with values around 15–20 MeV. E
mpirical information suggests that the Λ-nucleus spin-orbit interaction s
hould be rather weak. Therefore\, we investigate also the spin-orbit inter
action and\, in particular\, the role of the antisymmetric spin-orbit forc
e in the Y N system. The chiral EFT approach yields a potential that conta
ins\, besides pseudoscalar meson exchanges (π\, K\, η)\, a series of con
tact interactions with an increasing number of derivatives. In this approa
ch a contact term representing an antisymmetric spin-orbit force arises al
ready at NLO. It induces 1P1–3 P1 transitions in the coupled (I = 1/2)
ΛN–ΣN system. The low-energy constant associated with the contact term
could not be pinned down by a fit to the existing ΛN and ΣN scattering
data as found in Ref. [3] and\, thus\, it was simply put to zero in that w
ork. However\, it turns out that its value can be fixed from investigating
the properties of the Λ hyperon in nuclear matter and\, specifically\, i
t can be utilized to achieve a weak Λ-nuclear spin-orbit potential [1].\n
\nReferences\n1. J. Haidenbauer and U.-G. Meißner\, Nucl. Phys. A 936\, 2
9 (2015).\n2. H. Polinder\, J. Haidenbauer\, and U.-G. Meißner\, Nucl. Ph
ys. A 779\, 244 (2006).\n3. J. Haidenbauer\, S. Petschauer\, N. Kaiser\, U
.-G. Meißner\, A. Nogga\, and W. Weise\, Nucl. Phys. A 915\, 24 (2013).\n
\nhttps://agenda.infn.it/event/7897/contributions/70542/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS1
URL:https://agenda.infn.it/event/7897/contributions/70542/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Combined analysis of πN->πN and πN->ππN in ChPT
DTSTART;VALUE=DATE-TIME:20150630T130000Z
DTEND;VALUE=DATE-TIME:20150630T132000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70541@agenda.infn.it
DESCRIPTION:Speakers: Dmitrij Siemens (Ruhr University\, Bochum)\nIn my ta
lk\, I will focus on the reactions πN->πN and πN->ππN\, which are stu
died at one-loop level in the frameworks of covariant and heavy baryon chi
ral perturbation theory. Performing combined fits to determine the relevan
t low-energy constants\, predictions are made for various observables. In
addition\, first attempts to include ∆(1232) and R(1440) as explicit deg
rees of freedom will be discussed. (PhysRevC.89.065211)\n\nhttps://agenda.
infn.it/event/7897/contributions/70541/
LOCATION:Building E\, Polo Fibonacci\, Pisa Room PS4
URL:https://agenda.infn.it/event/7897/contributions/70541/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hadronic weak interaction: The NPDGamma experiment
DTSTART;VALUE=DATE-TIME:20150630T072500Z
DTEND;VALUE=DATE-TIME:20150630T080500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70540@agenda.infn.it
DESCRIPTION:Speakers: Libertad Barrón-Palos (Universidad Nacional Autóno
ma de México\, Ciudad de Mexico)\nThe measurement of very small parity-vi
olating (PV) observables in few-nucleon systems\, where nuclear wave funct
ions are calculable\, is a via for understanding the hadronic weak interac
tion (HWI)\, which remains enigmatic due to the dominance of the strong in
teraction in hadronic systems and the non-perturbative nature of Quantum C
hromodynamics at low energies. Additionally\, the study of the strangeness
-conserving HWI could help to understand phenomena that have been observed
in the strangeness-changing sector and that cannot be explained in the fr
amework of existing theories\, like the dominance of the ∆I = 1/2 channe
l in the decay of kaons or the relative weak amplitudes in the non-leptoni
c decay of hyperons. The strangeness-conserving HWI also offers the possib
ility to study neutral currents at low energies\, since charged currents a
re suppressed for the ∆I = 1 nucleon-nucleon interactions. The ∆I = 1
channel\, accessible through the exchange of pions\, dominates the strong
interactions between nucleons at low energies. The availability of very in
tense neutron sources has allowed the development of experiments to measur
e PV effects in nuclear interactions between polarized slow neutrons and l
ight nuclei with sensitivity in the 10−8 level. A pioneer among these is
the NPDGamma experiment\, which last year completed data acquisition at t
he Spallation Neutron Source at the Oak Ridge Natiobal Laboratory to deter
mine the PV asymmetry in the spatial distribution of the gamma rays emitte
d in the capture of polarized cold neutrons by protons\, Aγ. This asymmet
ry is dominated by the ∆I = 1 3S1 − 3P1 parity-odd transition in the n
− p system\, therefore it is related to the weak coupling that characte
rizes the exchange of one pion in the HWI\, h1π. A statistical uncertaint
y of ∼ 1.3 × 10−8 was achieved in the determination of Aγ. I will de
scribe the experiment and discuss preliminary results\, as well as their c
omparison with theoretical calculations and previous experimental results.
\n\nhttps://agenda.infn.it/event/7897/contributions/70540/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70540/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Studies of light nuclei in chiEFT: A status report
DTSTART;VALUE=DATE-TIME:20150630T080500Z
DTEND;VALUE=DATE-TIME:20150630T084500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70539@agenda.infn.it
DESCRIPTION:Speakers: Rocco Schiavilla (Jefferson Lab/Old Dominion Univers
ity\, Norfolk)\nA status report on chiEFT studies of light-nuclei electro-
weak structure and dynamics is provided\, including electromagnetic elasti
c form factors of few-nucleon systems\, magnetic moments and M1 radiative
widths in A=6-10 nuclei\, the pp weak fusion and muon weak captures on deu
teron and 3He\, and a number of parity-violating processes induced by hadr
onic weak interactions.\n\nhttps://agenda.infn.it/event/7897/contributions
/70539/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70539/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pion--nucleon scattering at low energies
DTSTART;VALUE=DATE-TIME:20150702T064500Z
DTEND;VALUE=DATE-TIME:20150702T072500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70538@agenda.infn.it
DESCRIPTION:Speakers: Bastian Kubis (University of Bonn)\nEver since Weinb
erg's seminal predictions of the pion-nucleon scattering amplitudes at thr
eshold\, this process has been of central interest for the study of chiral
dynamics involving nucleons. Quantities like the scattering lengths or t
he pion-nucleon sigma-term are fundamental quantities characterizing the e
xplicit breaking of chiral symmetry by means of the light quark masses. O
n the other hand\, pion-nucleon dynamics also strongly affects the long-ra
nge part of nucleon--nucleon potentials\, and hence has a far-reaching imp
act on nuclear physics. I will review various approaches to analyze pion-n
ucleon scattering in the framework of baryon chiral perturbation theory--i
n the heavy-baryon formalism\, or using different manifestly covariant for
mulations. Finally\, I will discuss the fruitful combination of dispersio
n-theoretical methods\, in particular in the form of Roy-Steiner equations
\, with chiral dynamics to determine pion-nucleon scattering amplitudes at
low energies with high precision.\n\nhttps://agenda.infn.it/event/7897/co
ntributions/70538/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70538/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Recent progress in hadron structure from Lattice QCD
DTSTART;VALUE=DATE-TIME:20150703T091000Z
DTEND;VALUE=DATE-TIME:20150703T095000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70537@agenda.infn.it
DESCRIPTION:Speakers: Martha Constantinou (University of Cyprus\, Nicosia)
\nUnderstanding hadron structure from first principles is considered a mil
estone of hadronic physics and numerous experiments have been devoted to i
ts study\, starting with the measurements of the electromagnetic form fact
ors more than 50 years ago. Lattice QCD (LQCD) is a powerful tool for the
ab inition calculation of hadron observables that are either well determin
ed experimentally\, or not easily accessible in experiment. Thus\, LQCD ma
y provide input to phenomenology\, as well as new input for beyond the Sta
ndard Model Physics.\n\nProgress in the simulation of LQCD has been impres
sive\, mainly due to improvements in the algorithms\, development of new t
echniques and increase in computational power\, that have enabled simulati
ons to be carried out at parameters very close to their physical values. I
n this talk I will review developments in hadron structure with focus on r
ecent achievements in the evaluation of nucleon quantities\, such as the a
xial charge\, electromagnetic form factors\, the Dirac and Pauli radii\, t
he quark momentum fraction and the spin content of the nucleon\, in view o
f simulations close or at the physical value of the pion mass. I will also
highlight selected results on hyperon and meson form factors.\n\nhttps://
agenda.infn.it/event/7897/contributions/70537/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70537/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nuclear chiral EFT in the precision era
DTSTART;VALUE=DATE-TIME:20150630T103000Z
DTEND;VALUE=DATE-TIME:20150630T111000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70536@agenda.infn.it
DESCRIPTION:Speakers: Evgeny Epelbaum (Ruhr University\, Bochum)\nChiral e
ffective field theory provides a systematically improvable perturbative ap
proach to deriving nuclear forces in harmony with the symmetries of QCD. C
ombined with modern few- and many-body methods\, this framework represents
a commonly accepted procedure for ab initio studies of nuclear structure
and reactions. Recently\, a new generation of nucleon-nucleon (NN) forces
up to fifth order in the chiral expansion has been developed [1\, 2]. By e
mploying an appropriate regularization in coordinate space\, which maintai
ns the analytic structure of the amplitude\, it was possible to significan
tly reduce the amount of finite-cutoff artefacts. In addition\, a simple a
pproach to estimating the theoretical uncertainty in few- and many-nucleon
calculations from the truncation of the chiral expansion was proposed [1]
. I will present the applications of the novel NN chiral potentials\, alon
g with the new analysis of the theoretical truncation errors\, to NN and n
ucleon-deuteron scattering and to the properties of 2H\, 3H\, 4 He and 6 L
i [1\, 2\, 3].\n\nReferences\n1. E. Epelbaum\, H. Krebs\, U.-G. Meißner\,
Eur. Phys. J. A 51\, no. 5\, 53 (2015).\n2. E. Epelbaum\, H. Krebs\, U.-G
. Meißner\, arXiv:1412.4623 [nucl-th].\n3. LENPIC Collaboration\, arXiv:1
505.07218 [nucl-th].\n\nhttps://agenda.infn.it/event/7897/contributions/70
536/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70536/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Unexpected chiral dynamics from lattice QCD calculations of nuclea
r systems
DTSTART;VALUE=DATE-TIME:20150630T095000Z
DTEND;VALUE=DATE-TIME:20150630T103000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70535@agenda.infn.it
DESCRIPTION:Speakers: Silas Beane (University of Washington\, Seattle)\nI
will review recent calculations of the properties and interactions of nucl
ei and hypernuclei from first principles using lattice QCD. Many interesti
ng observables have now been computed at several (unphysical) values of th
e quark masses and the first rudimentary extrapolations to the physical po
int have been performed. The resulting picture of the quark mass dependenc
e of nucleon and nuclear observables is somewhat surprising from the persp
ective of chiral dynamics.\n\nhttps://agenda.infn.it/event/7897/contributi
ons/70535/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70535/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kaons at CERN: The NA62 experimental program
DTSTART;VALUE=DATE-TIME:20150702T091000Z
DTEND;VALUE=DATE-TIME:20150702T095000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70534@agenda.infn.it
DESCRIPTION:Speakers: Augusto Ceccucci (CERN)\nKaons are a laboratory wher
e a broad physics programme can be addressed. From the study of fundamenta
l symmetries to the exploration of the hadron structure\, from the search
for phenomena beyond the Standard Model to the comprehension of the simple
st hadronic states\, many investigations profit from the remarkably clean
theoretical and experimental environment provided by kaons. NA62 is a new
experiment at CERN exploiting the high energy protons from the Super Proto
n Synchrotron. The main goal of NA62 is the study of very rare kaon decays
and to this purpose the experiment incorporates state-of-the-art detector
s including innovative trackers\, high performance calorimetry and complet
e particle identification capability. The presentation will review the sta
tus of the experiment and its perspectives.\n\nhttps://agenda.infn.it/even
t/7897/contributions/70534/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70534/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Status of chiral perturbation theory for light mesons
DTSTART;VALUE=DATE-TIME:20150702T095000Z
DTEND;VALUE=DATE-TIME:20150702T103000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70533@agenda.infn.it
DESCRIPTION:Speakers: Gerhard Ecker (University of Vienna)\nI will review
some recent activities in mesonic chiral perturbation theory. Our present
knowledge of low-energy constants in the strong sector up to and including
next-to-next- to-leading order will be discussed. I will also assess the
present status of CKM unitarity. Further topics are pion polarizabilities\
, kaon and η decays.\n\nhttps://agenda.infn.it/event/7897/contributions/7
0533/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70533/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meson resonances on the lattice
DTSTART;VALUE=DATE-TIME:20150702T103000Z
DTEND;VALUE=DATE-TIME:20150702T111000Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70532@agenda.infn.it
DESCRIPTION:Speakers: Robert Edwards (Jefferson Lab)\nThere has been recen
t\, significant\, advances in the determination of the meson spectrum of Q
CD. Current efforts have focused on the development and application of fin
ite-volume formalisms that allow for the determination of scattering ampli
tudes as well as resonance behaviour in coupled channel systems. I will re
view some of these recent developments\, and demonstrate the viability of
the method in meson systems.\n\nhttps://agenda.infn.it/event/7897/contribu
tions/70532/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70532/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extracting (pion) form factors from finite volume lattices
DTSTART;VALUE=DATE-TIME:20150701T072500Z
DTEND;VALUE=DATE-TIME:20150701T080500Z
DTSTAMP;VALUE=DATE-TIME:20200606T075946Z
UID:indico-contribution-7897-70531@agenda.infn.it
DESCRIPTION:Speakers: Hidenori Fukaya (Osaka University)\nIn lattice QCD s
imulations\, there is a strong tendency to over-estimate the form factors
(and therefore\, under-estimate the related charge radii) of pions and oth
er hadrons. In fact\, the three major systematic in lattice QCD: finite la
ttice spacing a\, lack of chiral symmetry\, and finite volume all could co
ntribute to the over-estimation of the form factors. This can be easily un
derstood within the chiral effective theory\, as a distortion of the chira
l logarithm:\n\n ln M_pi^2 -> ln (M_pi^2+delta m^2
)\,\n\nwhere M_pi denotes the pion mass\, and delta m is the unphysical ma
ss scale induced by finite a\, and/or explicit chiral symmetry breaking\,
and/or finite lattice size.\n\nIn this talk\, we would like to focus on th
e finite volume effects using chiral perturbation theory (Ref. 1) and disc
uss how to avoid such an over-estimation of the (pion) form factors. We al
so present our recent lattice results with dynamical overlap (Ref. 2 and s
ee attached Figure) and M"obius domain-wall fermions (Ref. 3).\n\nReferenc
es \n\n1. H. Fukaya and T. Suzuki\, Phys. Rev. D 90\, no. 11\, 114508 (20
14) [arXiv:1409.0327].\n2. JLQCD collaboration\, Phys. Rev. D 90\, no. 3\
, 034506 (2014) [arXiv:1405.4077].\n3. JLQCD collaboration\, work in progr
ess.\n\nhttps://agenda.infn.it/event/7897/contributions/70531/
LOCATION:Building E\, Polo Fibonacci\, Pisa Aula Magna
URL:https://agenda.infn.it/event/7897/contributions/70531/
END:VEVENT
END:VCALENDAR