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Parallel sessions on Flavor and Precision Physics
In light of the recent LHCb observation of CP violation in the charm sector,
we review Standard Model (SM) predictions in the charm sector and in particular for $\Delta A_{CP}$. We get as an upper bound in the SM $| \Delta A_{CP} ^{\rm SM}| \leq 3.6 \times 10^{-4}$, which can be compared to the LHCb measurement of
$\Delta A_{CP}^{\rm LHCb-2019} = (-15.4 \pm 2.9) \times 10^{-4}$. We discuss...
Decay modes with two oppositely charged leptons of different flavor correspond to lepton flavor violating (LFV) decays and are essentially forbidden in the Standard Model (SM) because they can occur only through lepton mixing. Decay modes with two leptons of the same charge are lepton-number violating (LNV) decays and are forbidden in the SM. Hence, decays of the form $D^0 \to hh'll’$ provide...
BESIII has collected data sets corresponding to integrated
luminosities of 2.93 fb-1, 3.19 fb-1 and 0.567 fb-1 at center-of-mass
energies of 3.773, 4.178, and 4.6 GeV, respectively. We report the
measurements of the decay constants fD(s)+, the semileptonic form
factors f_P(0), the CKM matrix elements |Vcs(d)|. These results are
important to test the LQCD calculations of fD(s)+ and f_P(0)...
Kaon physics is one of the most powerful probes of physics beyond the standard model (SM), and sensitive to high scale new physics.
The exciting topic in kaon physics which gets attention is the discrepancy in the direct CP violation in $K \to \pi \pi$ decays, $\epsilon'/\epsilon$. Current progress of lattice calculations enables us to predict the $\epsilon'/\epsilon$ accurately, and the SM...
The NA48/2 experiment at CERN reports the first observation of the K± → π± π0 e+ e− decay from an exposure of 1.7×10^11 charged kaon decays recorded in 2003−2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region. The study of the kinematic space shows evidence for a structure dependent contribution in...
The NA62 experiment at CERN SPS was designed to measure BR(K+ -> pi+ nu nu-bar) with in-flight decays, a novel technique for this channel. NA62 took its first physics data in 2016, reaching the sensitivity to the decay at the Standard Model BR. The experiment collected 10 times more statistics in 2017 and a similar amount of data is expected from the 2018 run.
The result on K+ to pi+ nu nu-bar...
Flavour anomalies before and after Moriond 2019: new emerging scenarios. This talk will basically explain the changes in the patterns of New Physics we have found in a model independent analysis.
Indications for lepton flavour universality violation in the mode B -> D(*) tau nu and B -> K(*) l+ l- have been of interest
and can be a hint for the New Physics effect.
We report new measurements on R(D) and R(D*) (branching ratio of B -> D(*) tau nu over B -> D(*) l nu where l + e, mu) the semi-leptonic tag method,
nd on R(K*) (branching ratio of B -> K* mu+ mu- over K* e+ e-).
A...
The concept of lepton universality, where the muon and tau particles are simply heavier copies of the electron, is a key prediction in the Standard Model (SM). In models beyond the SM, lepton universality can be naturally violated with new physics particles that couple preferentially to the second and third generation leptons. Over the last few years, several hints of lepton universality...
We calculate multi-parton contributions to the inclusive $\bar{B}\to X_d\ell^+\ell^+$ decay, which turn out to be considerable but were never considered before. We also investigate the log-enhanced QED corrections and the resonance effects induced by the up-loop amplitudes, in additional to the charm-loop ones that also appear in the b to s transition. After that, employing the other NNLO QCD,...
The results of a search for charged lepton flavor violating decays tau->3mu, using pp collisions at sqrt(s)=13 TeV at LHC, are presented. This analysis uses the data collected by CMS in 2016, corresponsing to a luminosity of 33 fb^-1, and exploits tau leptons produced in W boson, D and B mesons decays.
Recent hints for lepton-universality violation in b->sll transitions could imply the existence of lepton-flavour violating B decays. The LHCb experiment is well suited for the search for these decays due to its large acceptance and trigger efficiency, as well as its excellent invariant mass resolution and particle identification capabilities. Recent results on searches for lepton-flavour...
Rare decays and processes involving interference with flavour-oscillation amplitudes are suitable for searches of New Physics. LHC has provided large samples of $B$ hadrons, and remarkable increases in sensitivities have been achieved in the decays $B^0_s$, $B^0 \to \mu^+\mu^-$ and in the search of CP violation in $B^0_s \to J/\psi\, \phi$. New, accurate results obtained with the ATLAS...
It is demonstrated that,if the lightest positive parity charm mesons are assumed to owe their existence to non-perturbative Goldstoneboson$D/D^∗$ scattering, various puzzles in the charm meson spectrum get resolved. Most importantly the ordering of the lightest strange and non-strange scalars becomes natural. It is demonstrated that the amplitudes for Goldstone boson-$D/D^∗$ scattering are...
This talk will cover recent progress on the charmonium and XYZ states at BESIII. I shall talk about the measurements of hadronic decays of the eta_c, chi_cJ, h_c, and psi(3686); new results on the X(3872) decaying into pi0 chi_c1 and omega J/psi; and new cross section measurements of e+ e- -> pi pi D Dbar and omega chi_c0. The upcoming data samples and the prospects for future charmonium and...
We perform Dalitz plot analyses of $J/\psi$ three-body hadronic decays to $\pi^+ \pi^-\pi^0$, $K^+ K^-\pi^0$ and $K^0_S K^{\pm} \pi^{\mp}$ using the isobar and Veneziano models. The $J/\psi$ is produced through the Inital-State-Radiation process. We also perform Dalitz plot analyses of $\eta_c$ three-body hadronic decays to $K^+ K^-\pi^0$ and $K^0_S K^{\pm} \pi^{\mp}$, where the $\eta_c$ is...
We report new results in heavy flavor spectroscopy, using pp collision data collected by the CMS experiment at the LHC, including the observation of two excited Bc states and the study of the B->J/Psi Lambda p decay. The first analysis is based on an event sample corresponding to a luminosity of 143 fb^-1 at sqrt(s)=13 TeV. The Bc excited states are observed in the Bc pipi invariant mass...
We calculate the weak decay form factors of doubly-heavy baryons using three-point QCD sum rules. The Cutkosky rules are used to derive the double dispersion relations. We include perturbative contributions and condensation contributions up to dimension five, and point out that the perturbative contributions and condensates with lowest dimensions dominate. An estimate of part of gluon-gluon...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure...
The MEG experiment took data at the Paul Scherrer Institute in the years 2009-2013 and published the most stringent limit on the charged lepton flavor violating decay $\mu \rightarrow e\gamma$: $BR(\mu \rightarrow e\gamma) <4.2 \times 10^{-13}$ @90% C.L.
The MEG detector has been upgraded in order to reach a sensitivity of $5 \times 10^{-14}$, which corresponds to an improvement of one order...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July 2018, the machine has...
Precision measurements of CP violating observables in the decays of b and c hadrons are powerful probes to search for physics beyond the Standard Model. The most recent results on CP violation in the decay, mixing and interference of both b and c hadrons obtained by the LHCb Collaboration with Run I and years 2015-2016 of Run II are reviewed. In particular world best constraints and world...
