Related papers: Possible Indications of New Physics in Bd-mixing a…
Motivated by recently observed disagreements with the SM predictions in $B$ decays, we study $b \to d, s$ transitions in an asymmetric class of $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ models, with a simple one-parameter structure of the…
I present quenched, lattice QCD calculations of the hadronic matrix elements relevant for B^0_{d(s)}-\bar B^0_{d(s)} and K^0-\bar K^0 mixing and briefly review the status of lattice predictions.
Results in the quenched approximation for SU(3) breaking ratios of the heavy-light decay constants and the $\Delta F=2$ mixing matrix elements are reported. Using lattice simulations at $6/g^2=5.7$, 5.85, 6.0, and 6.3, we directly compute…
Flavour physics offers interesting probes for the exploration of the Standard Model and the search for new physics. In these lectures, we focus on B- and K-meson decays, introduce the concept of low-energy effective Hamiltonians to describe…
We present a lattice-QCD calculation of the hadronic form factors for $B$-meson semileptonic decays computed using the highly improved staggered quark action for both valence and sea quarks on the MILC collaborations 2+1+1-flavor ensembles…
We calculate the leptonic decay constants of heavy-light pseudoscalar mesons with charm and bottom quarks in lattice quantum chromodynamics on four-flavor QCD gauge-field configurations with dynamical $u$, $d$, $s$, and $c$ quarks. We…
We investigate the pure penguin process $B^-\to \pi^-\phi$ using QCD factorization approach to calculate hadronic matrix elements to the $\alpha_s$ order in some well-known NP models. It is shown that the NP contributions in R-parity…
We discuss the B-physics signature of a supersymmetric U(2) flavor model in which the third generation scalars are relatively light (electroweak scale masses). We impose current experimental constraints on such a framework and obtain…
We present results for hadrons containing a strange quark in quenched lattice QCD. We calculate masses and decay constants using 60 gauge configurations with an O(a)-improved fermion action at beta = 6.2. Using the rho mass to set the…
I review recent progress in lattice computations relevant for $B$- and charm physics, focusing on decay and mixing amplitudes with a direct impact on CKM analysis. Emphasis is put on the interplay with the upcoming new generation of…
Recent precise measurements of sin 2 beta from the B-factories (BABAR and BELLE) and a better known strange quark mass from lattice QCD make precision tests of predictive texture models possible. The models tested include those hierarchical…
The study of b-hadrons made possible a great number of benchmark results in flavour physics. In recent years a lot of effort in understanding their dynamics has been done. These studies can represent a possible avenue for the discovery of…
We study contributions of quark-squark-gluino interactions in Minimal Supersymmetric Standard Model (MSSM) to B->PP (PP =Kpi, pipi, KK) decays using QCD improved factorization method for the evaluation of the hadronic matrix elements and…
Heavy-meson semileptonic decays calculations on the lattice are reviewed. The focus is upon obtaining reliable matrix elements. Errors that depend upon the lattice spacing, $a$, are an important source of systematic error. Full $O(a)$…
We present results for the matrix elements of the additional $\Delta S=2$ operators that appear in models of physics beyond the Standard Model (BSM), expressed in terms of four BSM $B$-parameters. Combined with experimental results for…
In a recent paper we studied the effect of new-physics operators with different Lorentz structures on the semileptonic $\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}$ decay. This decay is of interest in light of the $R({D^{(*)}})$ puzzle in…
In this letter, we consider the constraints imposed by the recent measurement of B_s - bar B_s mixing on the new physics contribution to the rare decay B_s --> mu+ mu-. New physics in the form vector and axial-vector couplings is already…
Measurements from the LHCb experiment and $B$ factories have revealed several discrepancies in angular observables of rare semileptonic $B$ decays involving the quark-level transition $b \to s \ell^+ \ell^-$. In this work, we conduct a…
We analyze the $B \to \phi K^{*}$ polarization puzzle in the Minimal Supersymmetric Standard Model (MSSM) including the neutral Higgs boson (NHB) contributions. To calculate the non-factorizable contributions to hadronic matrix elements of…
After reviewing the theoretical uncertainties entering the Standard Model determination of the mass difference of the neutral $B_s$-$\bar B_s$ meson system, $\Delta M_s^{\rm SM}$, we discuss the implications of its updated value for new…