Theoretical progress in describing the B-meson lifetimes

The present status of the theoretical estimates of the difference between the widths of the neutral Bs-mesons and of the B-meson lifetime ratios is reviewed. In particular, the lattice results for the matrix elements of the relevant (delta B=2)-operators are updated and the first lattice QCD results for the matrix elements of (delta B=0)-operators are presented. In both cases, the NLO perturbative QCD corrections in the coefficient functions have been included. The theoretically updated results are: (delta Gamma/Gamma)_{Bs} = (7 +/- 4) %, tau(B+)/tau(Bd) = 1.07(3) and tau(Bs)/tau(Bd) = 1.00(2).Comment: 14 pages (5 figures), Extended version of the talk given at IEC-HEP Budapest, 200

A model to accommodate the BB-physics anomalies

After briefly reviewing the status of the $B$-physics anomalies, describing the challenges of building a scenario of physics beyond the Standard Model that can accommodate the observed departures from lepton flavor universality, I discuss a new model, based on extending the Standard Model by two light [$\mathcal{O}(1\,\mathrm{TeV})$] scalar leptoquarks. That model, in addition to satisfying a number of flavor physics constraints both at low and high energies, also allows for a $SU(5)$ unification.Comment: 8 pages writeup, talk given at the 53rd Rencontres de Moriond EW201

Radiative decays of charmonia on the lattice

We present the results of our lattice QCD study of the hadronic matrix elements relevant to the physical radiative J/psi -> eta_c gamma and hc -> eta_c gamma decays. From computations with Nf=2 dynamical quark in twisted mass QCD at four lattice spacings, we were able to take the continuum limit and obtained Gamma(J/psi -> eta_c gamma) = 2.64(11) keV and Gamma(hc -> eta_c gamma) = 0.72(5) MeV. We also computed the the hyperfine splitting and found that it does not depend from the sea quark mass and we obtain Delta = m_J/psi - m_eta_c = 112(4) MeV.Comment: 8 pages, 4 figures. Proceedings of the "Xth Quark Confinement and the Hadron Spectrum", 8-12 October 2012, TUM Campus Garching, Munich, German

Heavy Quark Phenomenology from Lattice QCD

Recent results relevant for the B-physics phenomenology, obtained from lattice QCD simulations by the APE Collaboration, are reviewed. This includes the B0-B0bar mixing amplitude, B-> pi semileptonic decay and the relative width difference of B0_s mesons, $(\Delta \Gamma/\Gamma)_{B_s}$.Comment: 4 page

Lattice QCD estimate of the ηc(2S)→J/ψγ\eta_{c}(2S)\to J/\psi\gamma decay rate

We compute the hadronic matrix element relevant to the physical radiative decay $\eta_{c}(2S)\to J/\psi\gamma$ by means of lattice QCD. We use the (maximally) twisted mass QCD action with Nf=2 light dynamical quarks and from the computations made at four lattice spacings we were able to take the continuum limit. The value of the mass ratio $m_{\eta_c(2S)}/m_{\eta_c(1S)}$ we obtain is consistent with the experimental value, and our prediction for the form factor is $V^{\eta_{c}(2S)\to J/\psi\gamma}(0)\equiv V_{12}(0)=0.32(6)(2)$, leading to $\Gamma(\eta_c (2S) \to J/\psi\gamma) = (15.7\pm 5.7)$ keV, which is much larger than $\Gamma(\psi (2S) \to \eta_c\gamma)$ and within reach of modern experiments.Comment: 19 pages, 4 fig