Related papers: Leptonic Constant from B Meson Radiative Decay
We derive the QCD$\times$QED factorization theorem governing the leptonic decay $B^-\to\mu^-\bar\nu_\mu(\gamma)$ at all orders in $\alpha_s$ and $\alpha$. Electromagnetic corrections to this decay probe multiple scales, which we disentangle…
We study the radiative and weak nonleptonic decays of vector B-mesons within the covariant confined quark model (CCQM) developed in our previous papers. First, we calculate the matrix elements and decays widths of the radiative decays…
Exclusive nonleptonic bottom meson decays are studied in the covariant osillator quark model using the factorization assumption. The main feature of this model is that it can simultaniously be applied to both heavy to heavy and heavy to…
We review here the physics of purely leptonic decays of pi-, K-, D+, Ds+, and B- pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak interaction based CKM matrix element of the constituent quarks…
We use lattice QCD to calculate the form factors $f_+(q^2)$ and $f_0(q^2)$ for the semileptonic decay $B_s\to K\ell\nu$. Our calculation uses six MILC asqtad 2+1 flavor gauge-field ensembles with three lattice spacings. At the smallest and…
A search for the rare radiative leptonic decay $D_s^+\to\gamma e^+\nu_e$ is performed for the first time using electron-positron collision data corresponding to an integrated luminosity of 3.19 fb$^{-1}$, collected with the BESIII detector…
Form factors parameterizing radiative leptonic decays of heavy mesons $% (B^{+}\to \gamma l^{+}\nu_{l}) $ for photon energy are computed in the language of dispersion relation. The contributing states to the absorptive part in the…
We study leptonic and semi-leptonic decays of D and B mesons. Use of the Hopping Parameter Expansion (HPE) for two-point functions allows us continuously to vary the pseudoscalar mass from below m_D up towards m_B. We compute the…
The semileptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+{\ell}+{{\nu}}_{\ell}$, and the two-body nonleptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+h$, (here $\chi_c$ and $h_c$ denote $(c\bar c[^3P_J])$ and $(c\bar c[^1P_1])$…
This study examines the rare decay $B \to K_0^*(1430)\,\ell^+ \ell^-$ as a possible probe for new physics beyond the standard model (SM). We first analyze this channel within the SM and then include scalar leptoquark (LQ) contributions. We…
We report on the status of an ALPHA Collaboration project to extract quantities for B physics phenomenology from Nf=2 lattice simulations. The framework is Heavy Quark Effective Theory (HQET) expanded up to the first order of the inverse…
Among the various "rare" semi-leptonic decays of $B$-mesons the $B \to K^* \ell^+ \ell^-$ mode is of special interest. This is because it has the highest branching ratio among all the semi-leptonic B decays within the SM. This channel also…
We address the non-perturbative calculation of the decay rate of inclusive semi-leptonic $B_{(s)}$ mesons decays from lattice QCD. Precise theoretical Standard Model predictions are key ingredients in searches for new physics. This type of…
The contributions of scalar and gauge leptoquarks into widths of $K^0_L \to e^{\mp} \mu^{\pm}$, $B^0 \to e^{\mp} \tau^{\pm}$ decays are calculated in the models with the vectorlike and chiral four color symmetry and with the Higgs mechanism…
In the framework of a QCD relativistic potential model we evaluate the form factors describing the exclusive decays B => \pi l nu and B => K l+ l-. The present calculation extends a previous analysis of B meson decays into light vector…
We present within the Standard Model the exclusive radiative decays B -> K*/rho gamma and B_(s/d) -> gamma gamma in QCD factorization based on the heavy-quark limit m_b >> Lambda_QCD. For the decays with a vector meson in the final state we…
Two-body non-leptonic decays of B mesons into PT and VT modes are calculated using the non-relativistic quark model of Isgur et al.. The predictions obtained for $B \to \pi D^*_2, \rho D_2^*$ are a factor of $3\sim 5$ below present…
We propose an approach for measuring the moments of the hadronic invariant mass distribution in semileptonic $B_{s}^{0}$ meson decays using a sum-of-exclusive technique. Using the present and foreseen knowledge about exclusive semileptonic…
Masses and decay constants of mesons containing a single $c$ or $b$ quark are described within the framework of heavy-quark symmetry. The $B_s^* - B_s$ and $\bar B^{*0} - \bar B^0$ mass splittings are found equal to within a fraction of an…
We discuss the computation of form factors for semi-leptonic decays of $\rm B$-, $\rm B_s$- mesons in lattice QCD. Considering in particular the example of the static $\rm B_s$ form factors we demonstrate that after non-perturbative…