相关论文: $B \to \rho \ell \nu_\ell$ Form Factors

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 on our on-going study of the $B_s \to K\ell\nu$ decay in $N_f=2+1$ lattice QCD. We employ fully relativistic setup in which the M\"obius domain-wall action is used for all quark flavors. The lattice cutoff is $a^{-1} \sim 2.5$…

We analyzed two form factors $T_1(q^2)$ and $T_2(q^2)$ which enter the $B\to K^* \ell^+ \ell^-$ decay rate and are accessible in the lattice calculations for $B \to K^* \gamma$. The extrapolation to $q^2=0$, necessary for $B\to K^* \gamma$…

I discuss QCD sum rules determinations of the form factors governing the decay $B \to \pi (\rho) \ell \nu$. For some of these form factors the computed dependence on the momentum transferred does not agree with the expectation from the…

We report on a recent computation of the form factors in semi-leptonic decays of the $\mathrm{B}_\mathrm{s}$ using Heavy Quark Effective Theory (HQET) formalism applied on the lattice. The connection of the form factors with the 2-point and…

We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=\eta, \eta',\phi$ and $\ell=\nu,e,\mu,\tau$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the…

Making use of the measurement of the $B\to K^*\gamma$ branching ratio together with the relations following from the limit of high recoil energy, we obtain stringent constraints on the values of the form-factors entering in heavy-to-light…

We present results of the first lattice QCD calculations of the weak matrix elements for the decays $B_c^+ \to D^0 \ell^+ \nu_{\ell}$, $B_c^+ \to D_s^+ \ell^+ \ell^-$ and $B_c^+ \to D_s^+ \nu \overline{\nu}$. Form factors across the entire…

We present a unified method for analysing form factors in B -> pi l nu-bar_l and B -> K* gamma decays. The analysis provides consistency checks on the q^2 and 1/M extrapolations necessary to obtain the physical decay rates. For the first…

We present the current status of the computation of the form factor $f_+ (q^2)$ for the semi-leptonic decay $\mathrm B_\mathrm s \to \mathrm K \ell \nu$ by the ALPHA collaboration. We use gauge configurations which were generated as part of…

We calculate the $B \to D^{(*)} \ell \nu$ form factors in 2+1 flavor relativistic lattice QCD by employing the M\"obius domain-wall action for all quark flavors. Our simulations are carried out at lattice cut-offs $a^{-1} \sim 2.5$, 3.6 and…

We describe the form factors for semileptonic B to rho l nu and radiative B to K* gamma decays with just two parameters and the two form factors for semileptonic B to pi l nu decays with three parameters. The parametrizations are…

I discuss recent progress in lattice calculations of $B \to D^{(*)} \ell \nu$ form factors, important for the precision determination of $|V_{cb}|$ in the Standard Model (SM), and for testing SM expectations of lepton flavor universality in…

We compute semi-leptonic $B_s$ decay form factors using Heavy Quark Effective Theory on the lattice. To obtain good control of the $1/m_b$ expansion, one has to take into account not only the leading static order but also the terms arising…

The rare decays $B^0 \to K^{*0} \mu^+ \mu^-$ and $B_s \to \phi \mu^+ \mu^-$ are now being observed with enough precision to test Standard Model predictions. A full understanding of these decays requires accurate determinations of the…

We examine the rates for the exclusive decays $B\to K^{(*)}\ell^+\ell^-$. We use the scaling predictions of the heavy quark effective theory to extract the necessary form factors from fits to various combinations of data. These data include…

We re-examine the determination of $|V_{cb}|$ from $B\to D \ell \nu$ in view of recent experimental and theoretical progress, discussing the parameterization of the form factors and studying the role played by the unitarity constraints. Our…

We present results of the first lattice QCD calculations of the weak matrix elements for the decays $B_c^+ \to D^0 \ell^+ \nu_{\ell}$, $B_c^+ \to D_s^+ \ell^+ \ell^-$ and $B_c^+ \to D_s^+ \nu \overline{\nu}$. Form factors across the entire…

We investigate the decays $B_c^- \rightarrow D_{s}^{(*)-}\ell^+\ell^-$ and $B_c^- \rightarrow D_{s}^{(*)-}\nu\bar{\nu}$ within the Standard Model (SM), employing perturbative QCD form factors that are sensitive to the wave functions of…

We investigate the decays $B_c^- \rightarrow \bar{D}^{(*)0}\ell^-\bar{\nu}_{\ell}$ and $B_c^- \rightarrow D^{(*)-}\ell^+\ell^-$ within the Standard Model (SM), employing perturbative QCD (pQCD) form factors that are sensitive to the wave…