相关论文: Effective Valence Quark Model and a Possible Dip i…
Long-distance QCD effects in $B_{d,s}\to\ell^+\ell^-\gamma$ decays are analyzed. We show that the contribution of the light vector-meson resonances related to the virtual photon emission from valence quarks of the $B$-meson, which was not…
We study the rare radiative leptonic decays $B_s\to\ell^+\ell^-\gamma$ ($\ell=e,\mu,\tau$) within the Standard Model, considering both the structure-dependent amplitude and bremsstrahlung. In the framework of the covariant confined quark…
We study the exclusive decays of $B\to K^{(*)}\ell^+ \ell^-$ by the results in the perturbative QCD with the heavy quark effective theory and lattice calculations. We obtain the form factors for the $B\to K^{(*)}$ transitions in the whole…
We investigate the exclusive rare $B_c\to D_{(s)}\nu_{\ell}\bar{\nu_{\ell}}$ and $B\to D_{(s)}\ell^+\ell^-$ ($\ell=e,\mu,\tau$) decays within the standard model and the light-front quark model constrained by the variational principle for…
We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…
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…
Using the $B_s$ meson wave function extracted from non-leptonic $B_s$ decays, we evaluate the short distance contribution of rare decays $B_s\to \ell^+\ell^-\gamma(\ell=e,\mu)$ in the standard model, including all the possible diagrams. We…
Long-distance effects in exclusive rare semileptonic transitions B -> (K, K*) are analysed within a relativistic quark model. The meson transition form factors, describing the meson amplitudes of the effective weak Hamiltonian, are…
Using the light-front quark model, we calculate the transition form factors, decay rates, and longitudinal lepton polarization asymmetries for the exclusive rare $B\to K\ell^+\ell^-(\ell=e,\mu,\tau$) decays within the standard model.…
Rare $\Lambda_b\to\Lambda l^+l^-$ and $\Lambda_b\to\Lambda\gamma$ decays are investigated in the relativistic quark model based on the quark-diquark picture of baryons. The decay form factors are calculated with the account of all…
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 study the rare semileptonic decays of $B_c$ mesons within the effective field theoretical framework of covariant confined quark model. The transition form factors corresponding to $B_c^+ \to D^{(*)+}$ and $B_c^+ \to D_s^{(*)+}$ are…
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 the results of the first computation related to the study of the spectator effects in the rare decay mode $B\to K \gamma \gamma $ within the framework of Standard Model. It is found that the account of these effects results in the…
The relativistic quark model based on the quasipotential approach with the QCD-motivate potential is employed for the calculation of the form factors of the $\Lambda_c\to p$ rare weak transitions. Their momentum dependence is explicitly…
Exclusive semileptonic B decays to radially excited charmed mesons and rare radiative B decay to the orbitally excited tensor K_2^*(1430) meson are investigated in the framework of the relativistic quark model based on the quasipotential…
We study, using a monte carlo approach, the rare decay $B\to X_s \ell^+ \ell^-$ including effects of the arbitrariness of the phase between the $\psi$ amplitudes and the perturbative amplitude, $b$-quark fermi motion inside the $B$ meson,…
In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order $\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which…
We calculate the differential branching fraction, lepton forward-backward asymmetry and direct CP asymmetry for $B_{d,s}\to\gamma\ell\bar{\ell}$ decays with an energetic photon. We employ factorization methods, which result in rigorous…
In this paper we investigate the next-to-leading power contribution to the $B_s \to \gamma\gamma$ and $B_s \to \gamma\ell\bar{\ell}$ decays from the strange quark mass effect with the dispersion approach which is QCD inspired and more…