相关论文: B Meson Semileptonic Form Factors from Unquenched …
We study SU(3)-breaking effects in the neutral B_d-\bar B_d and B_s-\bar B_s systems with unquenched N_f=2+1 lattice QCD. We calculate the relevant matrix elements on the MILC collaboration's gauge configurations with asqtad-improved…
We present results from quenched lattice QCD for the form factors for the decay $B\to\rho l\nu$. The calculations are performed using a nonperturbatively improved action and operators at two values of the lattice spacing. The bottom quark…
We report the first lattice QCD calculation of the form factors for the standard model tree-level decay $B_s\to K \ell\nu$. In combination with future measurement, this calculation will provide an alternative exclusive semileptonic…
We present an update of the Fermilab-MILC Collaboration's calculation of hadronic matrix elements for B^0-\bar{B^0} mixing. This work is a more extended analysis than our recent publication of the SU(3)-breaking ratio xi [arXiv:1205.7013].…
We propose a strategy to compute form factors entering the semileptonic decay channel of $B$ mesons into orbitally excited (P wave) $D^{**}$ charmed mesons on the lattice using, for the first time, realistic charm quarks having a finite…
In this contribution we compute some nonleptonic and semileptonic decay widths of $B_s$ mesons, working in the context of constituent quark models \cite{Albertus:2014gba, Albertus:2014bfa}. For the case of semileptonic decays we consider…
We calculate the B-meson decay constants f_B, f_Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the…
We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$. The computations are performed in the…
We present a study of leptonic $B$ meson decay constants in lattice QCD with two flavors ($N_f=2$) of light dynamical quarks using NRQCD for the heavy quark. Gauge configurations are generated with a renormalization-group improved gauge…
The quark flavor sector of the Standard Model is a fertile ground to look for new physics effects through a unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. We present a lattice QCD calculation of the scalar and the vector form…
I present two recent pieces of work on semileptonic $B \to \pi, \rho$ decays where it is shown how lattice QCD calculations can be used to test heavy-quark symmetry and determine phenomenologically relevant quantities despite the limits on…
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…
Quark model results for the $B\to \pi,\rho$ decays are analysed, making use of the dispersion formulation of the model: The form factors at $q^2>0$ are expressed as relativistic invariant double spectral representation over invariant masses…
We present a lattice determination of the hadronic susceptibilities that, thanks to unitarity and analyticity, constrain the form factors entering the semileptonic $b\rightarrow c$ transitions. We evaluate the transverse and longitudinal…
We present the status of our ongoing calculation of the zero-recoil form factor for the semileptonic decay $\bar{B}^0\rightarrow D^{*+}l^-\bar{\nu}$ using lattice QCD with 2+1+1 flavours of highly improved staggered quarks in the sea (the…
The form factors for the semi-leptonic B->D and B->D* decays are evaluated in quenched lattice QCD at two different values of the coupling, beta=6.0 and 6.2. The action and the operators are fully O(a) non-perturbatively improved. The slope…
We suggest to study the $B_{s}$ and its excitations $B_{sJ}$ in the $B_c$ decays. We calculate the $B_c\to B_{sJ}$ and $B_c\to B_{J}$ form factors within the covariant light-front quark model, where the $B_{sJ}$ and $B_{J}$ denote an s-wave…
In this work, we study the semileptonic decay modes $B_s^0\to \pi^+\pi^-\ell^+\ell^-$ and $D_s^+\to \pi^+\pi^-\ell^+ \nu$ in the kinematics region where the $\pi^+\pi^-$ system has a invariant mass in the range $0.5$-$1.3$ GeV. These…
We present the new analysis of the semileptonic B decays in the framework of the relativistic quark model based on the quasipotential approach. Decays both to heavy D^{(*)} and light \pi(\rho) mesons are considered. All relativistic effects…
We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD calculation utilizes a nonrelativistic QCD formulation for the b valence quarks, the…