Related papers: Study of $b\to c$ induced $\bar{B}^* \to V \ell \b…
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…
With the full data sample of $772 \times 10^6$ $B{\bar B}$ pairs recorded by the Belle detector at the KEKB electron-positron collider, the decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ is studied with the hadronic $\tau$ decays…
Motivated by the powerful capability of measurement for the $b$-flavored hadron rare decays at LHC and SuperKEKB/Belle-II, the nonleptonic $\bar{B}^{\ast}$ ${\to}$ $D\bar{D}^{\ast}$, $D{\rho^-}$, $DK^{\ast-}$, ${\pi}D^{\ast}$ and…
The extension of the standard model to include a single scalar or vector leptoquark has been shown to account for the observed deviations in the lepton flavor universality ratios in the $b \to c \ell \nu_{\ell}$ and $b \to s \ell \ell$…
In light of the LHCb observations about the $B_s \to D_s^{(*)}\ell \nu_\ell$ semileptonic decays, we study these channels within the Standard Model framework of covariant confined quark model. The necessary transition form factors are…
Based on $10.64~\mathrm{fb}^{-1}$ of $e^+e^-$ collision data taken at center-of-mass energies between 4.237 and 4.699 GeV with the BESIII detector, we study the leptonic $D^+_s$ decays using the $e^+e^-\to D^{*+}_{s} D^{*-}_{s}$ process.…
B --> rho l nu decay is analyzed in the effective theory of heavy quark with infinite mass limit. The matrix element relevant to the heavy to light vector meson semileptonic decays is parametrized by a set of four heavy flavor-spin…
Semileptonic and leptonic B decays are analyzed in the framework of the relativistic quark model. Special attention is payed to the decays involving $\tau$ lepton. It is found that the calculated particular decay branching fractions are…
We study exclusive $B_s$ decays to final states with $\eta$ and $\eta^\prime$, induced by the rare $b \to s \ell^+ \ell^-$ and $b \to s \nu \bar \nu$ transitions. Differential decay rates and total branching fractions are predicted in the…
We present precise theoretical predictions for the absolute branching fractions of $\Lambda_c^+ \to \Lambda \ell^+ \nu_\ell\,(\ell=e,\mu)$ decays in the covariant confined quark model. This study is motivated by two recent and accurate…
Recent experimental results for the ratio of the branching fractions of $\bar B \to D^{(*)}\tau \nu_\tau$ and $B\to D^{(*)} \mu \nu_\mu$ decays came as a surprise and lead to a discussion of possibility to constraining new physics through…
We report new measurements of the branching fraction $\cal B(D_s^+\to \ell^+\nu)$, where $\ell^+$ is either $\mu^+$ or $\tau^+(\to\pi^+\bar{\nu}_\tau)$, based on $6.32$ fb$^{-1}$ of electron-positron annihilation data collected by the…
Within the framework of perturbative QCD approach, we study the charmless two-body decays into final states involving one axial-vector (A), $a_1(1260)$ or $b_1(1235)$, and one vector (V), namely $\rho(\omega,\phi)$. Using the decays…
B physics has played a prominent role in investigations of new physics effects at low-energies. Presently, the largest discrepancy between a standard model prediction and experimental measurements appears in the branching ratio of the…
We determine the rates of the $B$ meson decays into a $K^{(*)}$ and an $\ell^+ \ell^-$ bound state, the leptonium, where $\ell = e,\mu,\tau$. The two spin states of the leptonium, the spin singlet and the spin triplet, couple to the axial…
We study the effects of the fourth generation of quarks on the total branching ratio and the lepton polarizations in $\bar{B}_{0}\rightarrow K_{0}^{\ast}(1430)l^{+}l^{-}$($l$ = $\mu $, $\tau $) decay. Taking fourth generation quark mass…
We investigate the exclusive semilpetonic decays of $\Lambda^{+}_{c}\to (\Lambda/n) \ell^{+} \nu_{\ell}~(\ell=e,\mu)$ within the standard model by using the light-front quark model (LFQM). The form factor behaviors are obtained from the…
We investigate the experimentally-accessible kinematic distributions of the $\bar B\to D^{(*)}\tau^-(\to\ell^-\bar\nu_\ell\nu_\tau)\bar\nu_\tau$ decays. Specifically, we study the decay rates as functions of the $B\to D^{(*)}$ transferred…
We briefly discuss the predictions of the heavy quark effective theory for the semileptonic decays of a heavy pseudoscalar to a light one, or to a light vector meson. We point out that measurement of combinations of differential helicity…
The study of flavour-changing neutral currents (FCNC) gives access to important tests of the Standard Model (SM) and allows to search for hints of beyond the SM phenomena. We present here the study of the very rare decays $B^0\rightarrow…