Related papers: Rare Radiative $B_{c}\rightarrow D_{s1}(2460)\gamm…
We study the decay $B_c \rightarrow D_s^* \gamma$. There are two mechanisms contributing to the process. One proceeds through the short distance $b{\rightarrow}s\gamma$ transition and the other occurs through weak annihilation accompanied…
In this work, the radiative Bc -> D*_s gamma decay is investigated in the framework of QCD sum rules. The transition form factors responsible for the decay are calculated. The branching ratio for this decay is estimated to be order of 10^-5…
We carry out a detailed study of exclusive radiative rare $B$-decays in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule technique with the description of final state vector mesons in terms…
We evaluate the branching ratios of the radiative decays $B \to K^* \gamma $, and $B \to K_1 \gamma $ in the framework of three-point function QCD sum rules. We find: $ \Gamma(B \to K^* \gamma) / \Gamma(b \to s \gamma) = 0.17 \pm 0.05$ and…
In this work, we use the QCD sum rule method to study the radiative decays of the vector and axial-vector $B_c$ mesons to each of three charmed strange mesons, $D_s$, $D^*_s$ and $D_{s1}$, through their dominant weak annihilation channels.…
In this article, we study the rare decays corresponding to $b \to d$ transition in the framework of the covariant confined quark model. The transition form factors for the channels $B^{+(0)} \to (\pi^{+(0)}, \rho^{+(0)},\omega)$ and $B_s^0…
We investigate the radiative B_c -> rho^+ gamma and B_c -> K^{*+} gamma decays in the standard model. The transition form factors are calculated in the framework of the light cone QCD sum rules method. We estimate the branching ratios of…
Considering the gluon condensate corrections, the form factors relevant to the semileptonic rare $B_c \rar D,D_s(J^{P}=0^{-}) l^{+}l^{-}$ with $l=\tau,\mu,e$ and $B_c \rar D,D_s(J^{P}=0^{-})\nu\bar{\nu}$ transitions are calculated in the…
In this paper, we study the rare radiative processes $B_c\to D_{sJ} ^{(*)}\gamma$ within the Standard Model, where $D_{sJ}^{(*)}$ stands for the meson $D_s^*$,~$D_{s1}(2460,2536)$ or ~$D_{s2}^*(2573)$. During the investigations, we consider…
Applying the perturbative QCD ( PQCD ) method, we study the decay $B_c\rightarrow D_s^*\gamma$ in the standard model and multiscale walking technicolor model. In the SM, we find that the contribution of weak annihilation is more important…
In this work we study the radiative decays of $B\to \rho (\omega)\gamma$ processes in the modified perturbative QCD approach, where the transverse momenta of the quark and gluons envolved in the interaction process are kept, and the Sudakov…
The radiative decays $ B^{*} (D^{*})\to B(D) \gamma$ are investigated in the framework of light cone QCD sum rules. The transition amplitude and decay rates are estimated.It is shown that our results on branching ratios of D meson decays…
The short-distance contribution due to the $c\to u\gamma$ penguin as well as long-distance contributions are considered in an analysis of $D\to V\gamma$ decays, the latter being dominant. The matrix elements for nine $D\to V\gamma$…
We predict contributions of higher $K$-resonances to the radiative rare decays $b\to s\gamma$, in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule method with the description of final state…
The rare $B_c \to D_{s,d}^{*} l^+ l^-$ decays are investigated in the framework of the three point QCD sum rules approach. Considering the gluon condensate corrections to the correlation function, the form factors relevant to these…
The branchings fractions of the rare $B_s$ decays are calculated in the framework of the QCD-motivated relativistic quark model. The form factors of the weak $B_s$ transitions to light mesons are expressed through the overlap integral of…
The radiative decays $ B^{*} (D^{*})\rightarrow B(D) \gamma$ are investigated in the framework of light cone QCD sum rules. The transition amplitude and decay rates are estimated.It is shown that our results on branching ratios of D meson…
Using the factorization approach and considering the contributions of the current-current, QCD penguin and electroweak penguin operators at the leading approximation, the decay amplitudes and decay widths of $B_q\to D_q(D_q^*) P$ and…
We analyze the double radiative B-meson decays B_s -> gamma gamma and B_d -> gamma gamma in QCD factorization based on the heavy-quark limit m_b >> Lambda_QCD. We systematically discuss the various contributions to these exclusive…
In this article, we calculate the $B_c^* \to B_c$ electromagnetic form-factor with the three-point QCD sum rules, then study the radiative decays $ B_c^{*\pm} \to B_c^{\pm} \gamma$. Experimentally, we can study the radiative transitions…