Coordinatori
Hadron decays, production and interaction: Session 1
- Pietro Colangelo (Istituto Nazionale di Fisica Nucleare)
- Alexis Pompili (Istituto Nazionale di Fisica Nucleare)
- Carlo Schiavi (Istituto Nazionale di Fisica Nucleare)
Hadron decays, production and interaction: Session 2
- Carlo Schiavi (Istituto Nazionale di Fisica Nucleare)
Hadron decays, production and interaction: Session 3
- Jose Pelaez (Universidad Complutense de Madrid)
Hadron decays, production and interaction: Session 4
- Alessandra Fanfani (Istituto Nazionale di Fisica Nucleare)
Hadron decays, production and interaction: Session 5
- Pietro Colangelo (Istituto Nazionale di Fisica Nucleare)
Hadron decays, production and interaction: Session 6
- Alexis Pompili (Istituto Nazionale di Fisica Nucleare)
Hadron decays, production and interaction: Session 8
- Stefania Bufalino (Istituto Nazionale di Fisica Nucleare)
I will first review the recent theoretical and phenomenological progress of studying multiple parton scattering at the LHC in both pp and heavy-ion collisions. I will then breifly summarise the existing experimental measurements. Finally, I will try to highlight the first triple parton scattering study by observing the triple J/psi production process with the CMS detector, and the first double...
Quarkonium measurements in proton-proton (pp) collisions represent a fundamental tool for studying quantum chromodynamics (QCD), due to the involvement of both perturbative and non-perturbative regimes and their interplay in the resonance formation process. In p--Pb collisions, quarkonium production is sensitive to the nuclear modifications on parton distribution functions and potentially to...
Under some assumptions on the hierarchy of relevant energy scales, we com-
pute the nonrelativistic QCD (NRQCD) long-distance matrix elements (LDMEs) for inclu- sive production of J/ψ, ψ(2S), and Υ states based on the potential NRQCD (pNRQCD) effective field theory. Based on the pNRQCD formalism, we obtain expressions for the LDMEs in terms of the quarkonium wavefunctions at the origin and...
Close-to-threshold photoproduction $\gamma{}p\rightarrow{}J/\psi{}p$ probes small-size gluon configurations in the proton. Under certain assumptions it allows us to study the proton properties, as gluonic GPDs, anomalous contribution to the mass of the proton, gravitational form factors, and the mass radius of the proton. A careful comparison of the experimental data with the theoretical...
Charm quarks, which are created at the beginning of heavy-ion collisions and interact with the produced quark-gloun plasma (QGPP) medium during all the stages of the system evolution, are useful probes of the partonic in-medium energy loss and the quark hadronisation. In particular, the measurement of charmed baryon-to-meson ratio $\Lambda_\text{c}^+/\text{D}^0$ is sensitive to the different...
Recent results published in [Nature Physics (2019)][1] by the BESIII collaboration revealed a substantial discrepancy of the Lambda baryon decay parameter with respect to the world average at the time.
We took this development as the starting point for a feasibility study of [CP violation tests in strange baryon decays][2] at next generation J/ψ factories. The proposed formalism allows for a...
This presentation will cover the branching fraction measurements of chi_cJ -> phi phi (J=0,1,2), eta_c(2S) -> pi+ pi- eta, chi_cJ -> Omega+ antiOmega- (J=0,1,2), and psi(3770) -> eta J/psi. The first three measurements are benefitted from the huge psi(2S) samples collected at BESIII and the transitions from psi(2S) to chi_cJ or eta_c(2S). The last one is based on e+ e- annihilation data sample...
BESIII has collected 2.93 and 7.33 fb^-1 of e+e- collision data samples at 3.773 and 4.128-4.226 GeV, which provide the largest dataset of DDbar and DsDs pairs in the world, respectively.
In this talk, we will report the updated measurements of |Vcs| in Ds+->tau+ nu and the form factor studies in Ds+->K+K- e+ nu and pi+pi- e+ nu. In addition, we will report the most updated amplitude...
Inspired by the recent observations of $T_{c\bar{s}0}^{0/++}$ in the the processes $B^0\to\bar{D}^0 D_s^+ \pi^-$ and $B^+\to D^- D_s^+ \pi^+$ by LHCb Collaboration, we investigate the decay properties of the $T_{c\bar{s}0}^{0}$ in a $D^{*}K^{*}$ molecule scenario, and the widths of $T_{c\bar{s}0}^{0}\to D^{0}K^{0}$, $D_{s}^{+}\pi^{-}$, $D_{s}^{*+}\rho^{-}$, $D_{s1}^{(\prime)+}\pi^{-}$, and...
The world’s largest sample of J/ψ events accumulated at the BESIII detector offers a unique opportunity to investigate η and η′ physics via two body J/ψ radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in η/η′ decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this report, including the observation...
The spectral reconstruction of Euclidean correlation functions is an alternative to standard lattice QCD analyses. Using this approach, inclusive hadronic decays are determined directly from first principles, including the $R$-ratio and hadronic decays of the tau-lepton. The computed decay rates are smeared with a known kernel, the achievable resolution of which is related to the spatial...
Hadronic spectral densities play a pivotal role in particle physics, a primer example being the R-ratio defined from electron-positron scattering into hadrons. To predict them from first principles using Lattice QCD, we face a numerically ill-posed inverse problem, due to the Euclidean signature adopted in practical simulations. Here we review the status of recent numerical approaches to the...
Hadronic spectral densities play a pivotal role in particle physics, a primer example being the R-ratio defined from electron-positron scattering into hadrons. To predict them from first principles using Lattice QCD, we face a numerically ill-posed inverse problem, due to the Euclidean signature adopted in practical simulations. Here we present a recent numerical analysis of the vector...
Studies of the e+e- annihilation into open-bottom final states are very important for understanding of the properties and nature of the bottomonium and bottomonium-like states. We report the first measurement of the inclusive σ(e+e− → bb̄ → DsX) and σ(e+ e− → bb̄ → D0X) cross sections in the energy range from 10.63 to 11.02 GeV. Based on these results, we determine σ(e+ e− → Bs X) in the same...
Based on the constraint formalism for the Dirac equation[1] the quarkonium states in a strong uniform magnetic field are studied. The relativistic equations governing the masses of the quarkonium consisting of various flavors in the singlet states are derived in the explicit form. The obtained spectrum is studied in detail. The derived spectrum is found to be in strong dependence...
Angular (ΔηΔφ) correlations of identified particles measured in ultrarelativistic proton-proton and heavy-ion collisions exhibit a number of features which depend on the collision system and particle type under consideration. Those features are produced by various mechanisms, such as (mini)jets, elliptic flow, resonance decays, and conservation laws. In addition, of particular importance are...
Scattering cross section measurements have been used to study the strong interaction between charged kaons and deuterons. However, these studies have not been successful in determining the scattering lengths of the strong interaction between $\rm K^{+}d$ and $\rm K^{-}d$. Moreover, the currently available theoretical predictions for this $\rm K^{-}d$ scattering parameter are largely based on...
The three-particle $K$-matrix, $\mathcal{K}_{\mathrm{df},3}$, is a scheme-dependent quantity that parametrizes short-range three-particle interactions in the relativistic-field-theory three-particle finite-volume formalism. In this talk, I briefly present our earlier calculation of the six-pion amplitude at next-to-leading order (NLO) in Chiral Perturbation Theory (ChPT) and our recent...
The femtoscopic technique provided insights into the previously experimentally inaccessible strong interaction between hadron pairs, including strangeness or charm. The ALICE Collaboration has, for the first time, extended such measurements to three-hadron and hadron-nucleus systems. Such studies provide a pivotal input to a better understanding of exotic nuclei and three-body dynamics,...
We present a model for the J/ψ Λ spectrum in B− → J/ψ Λ p ̄ decays, including the PΛ_{psi s} (4338)
baryon recently observed by the LHCb collaboration. We assume production via triangle diagrams
which couple to the final state via non-perturbative interactions which are constrained by heavy-
quark and SU3-flavor symmetry. The bulk of the distribution is described by a triangle diagram
with...
The talk will report on the most recent results by the CMS collaboration on the ration between the $B^0_s$ and $B^+$ production ratio $f_s/f_u$.
We perform a theoretical study of the D+s → π+π+π−η decay. We look first at the basic D+s decay at the quark level from external and internal emission. Then hadronize a pair or two pairs of qq¯ states to have mesons at the end. Posteriorly the pairs of mesons are allowed to undergo final state interaction, by means of which the
a0(980), f0(980), a1(1260), and b1(1235) resonances are...
The LHCb collaboration has recently reported the largest CP violation effect from a single amplitude, as well as other giant CP asymmetries in several BB-meson decays into three charmless light mesons. It is also claimed that this is predominantly due to ππ→KKˉππ→KKˉ rescattering in the final state, particularly in the 1 to 1.5 GeV region. In these analyses the ππ→KKˉππ→KKˉ amplitude is by...
We study the hadronic production of $D$-wave states of $\bar bc$ quarkonium. The relative yield of such states is estimated for kinematic conditions of LHC experiments. The direct $B_c(D)$ production is complemented by NRQCD contributions being the same order $O(v^4)$. The NRQCD matrix elements are estimated within naive velocity scaling rule.
The structure of nucleon resonances (N), as revealed via N electroexcitation amplitudes, provide unique information on the many facets of the strongly coupled QCD (sQCD) regime. These amplitudes give insight into sQCD dynamics underlying the generation of a variety of nucleon resonances having different structural features. Exploration of excited nucleon structure in the spacelike region...
We propose a phenomenological extended vector meson dominance model for the baryon electromagnetic structure, and it is found that the current experimental data on the Lambda, Sigma, and Xi electromagnetic form factors in the time-like region can be well described.
The electromagnetic transition form factors of the nucleon provide important information on the internal structure of hadrons. A model-independent dispersive calculation of the Electromagnetic form factors N∗(1520)→N at low energies will be presented. Taking pion rescattering into consideration, we derived dispersive relations for the N∗(1520)→N TFFs that relate space-like and time-like...
In the quest of understanding the nature of neutron stars, the study of the nuclear equation of state (EoS) plays a pivotal role. For constraining the latter, a comprehensive knowledge of the strong interaction among hadrons is crucial. However, probing these interactions in scattering experiments is challenging for strange baryons due to the unstable nature of hyperon beams and thus the...
The production cross section of charm hadrons in hadronic collisions can be calculated using the factorisation approach as a convolution of three factors: the parton distribution functions (PDFs), the hard-scattering cross section at the partonic level, and the fragmentation functions of the produced heavy quarks into given species of heavy-flavour hadrons, which is assumed to be universal for...
In this talk, I will introduce an alternative method of derivative expansion to extract the hadron-hadron potential from Nambu-Bethe-Salpeter (NBS) wave functions that is more efficient in handling large nonlocality. While the HALQCD method has become popular for obtaining hadron interactions from lattice QCD simulations, its derivative expansion has been criticized for its unclear systemic...
Renormalizability of an effective field theory allows one
to perform a systematic expansion of the calculated observable
quantities in terms of some small parameter in accordance with
a certain power counting.
We consider chiral effective field theory in application to the
nucleon-nucleon interaction
at next-to-leading order in the chiral expansion.
The analysis of the...
The study of a heavy meson decaying to three lighter mesons can be described, in general, as quasi-two-body processes through the production of resonance intermediate states. To understand the dynamics of these processes, a full amplitude analysis of the corresponding Dalitz Plot is necessary. The most traditional way to describe it is to use the so-called Isobar Model where the total...
At the large distances compared to the chiral symmetry breaking scale, a four quark state $\bar Q \bar Q q q$, where $Q$ ($q$) is the heavy (light) quark, can be approximated by two asymptotic $\bar Q q$ mesons and one can analyze the meson-meson potentials to explore the long-range strong force in such systems. To this end, we study the potential between two bottom mesons in the heavy quark...
