相关论文: Radiative $B \to K^* \gamma $ transition in QCD
In this article, the electroweak transition form factors of $\Lambda_b\to\Lambda_c$ and $\Xi_b\to\Xi_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating…
Using the form factors obtained from holographic AdS/QCD and QCD sum rules, we predict the differential branching ratio and longitudinal polarization fraction for the rare $B\to K^* \nu \bar\nu$ decay. This is an interesting decay channel…
The upper limit of the branching ratio of the rare $\Xi_b^-\rightarrow \Xi^- \gamma$ decay is obtained as $BR(\Xi_b^-\rightarrow \Xi^- \gamma)<1.3\times10^{-4}$ by the LHCb. In the present work we study this decay within the light cone QCD…
We discuss some selected topics in rare B decays in the context of the standard model and compare theoretical estimates with available data. Salient features of the perturbative-QCD and power corrections in the decay rate for $B \to X_s +…
With the perturbative QCD approach based on $k_T$ factorization, we study the pure annihilation type radiative decays $B^0 \to \phi\gamma$ and $B^0\to J/\psi \gamma$. We find that the branching ratio of $B^0 \to \phi\gamma$ is…
This article is devoted to calculating the form factors of $B_c \to D^{*}$, $B_c \to D$, $B_c \to D_s^{*}$ and $B_c \to D_s$ transitions in the framework of three-point QCD sum rules. At the QCD side, the contributions of…
The transition form factors responsible for the radiative $\Sigma_Q \to \Lambda_Q \gamma$ and $\Xi_Q^\prime \to \Xi \gamma$ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the…
We argue that the factorizable $c\bar c$ long- and short-distance contributions to the $B\to K^*\gamma$ amplitude vanish, separately, if defined in a gauge-invariant way. Therefore, the $c\bar c$ states contribute to the radiative decay…
Motivated by the experimental measurements of $D^0$ radiative decay modes we have proposed a model to study the $D^0\to \bar{K}^{*0}\gamma$ decay, by establishing a link with $D^0\to \bar{K}^{*0}V$ $(V=\rho^0,\, \omega)$ decays through the…
Within the frameworks of the light-front quark model (LFQM) and chiral perturbation theory (ChPT) of $O(p^6)$, we reevaluate the form factors of the $K^+ \to \gamma$ transition. We use these form factors to study the decay of $K^+ \to e^+…
We report measurements of the radiative decay B --> K^*\gamma. The analysis is based on a data sample containing 85.0*10^6 B meson pairs collected by the Belle detector at the KEKB storage ring. We measure branching fractions of Br(B^0 -->…
We calculate the main observables in $B_{u,d}\to (\rho,\omega,K^*)\gamma$ and $B_s\to (\bar K^*,\phi)\gamma$ decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant…
The method of QCD sum rules has proven to be particularly useful in heavy quark physics, where a small distance scale is provided by the inverse heavy quark mass. We present two new examples for the application of this method to B-physics:…
Implications of the recent new measurements of $B\to K_1\gamma$ by Belle are examined. It is shown that the new branching ratio $\calB(B\to K_1(1270)\gamma)$ requires very large form factor compared to the theoretically predicted one. This…
We study the effect of supersymmetric contributions to the effective quark transition $b\to s\gamma\gamma$, including leading order QCD effects. We apply the discussion to the decay $B_s\to\gamma\gamma$. Even though one-particle irreducible…
We investigate the radiative process of the $\Lambda_b\rightarrow \Lambda \gamma$ in the standard model as well as models with one or two compact universal extra dimensions. Using the form factors entered to the low energy matrix elements,…
We calculate the electron spectrum of semileptonic decays of B-mesons into non-charmed hadrons. The shape of the spectrum obtained from QCD sum rules is in general agreement with quark model calculations. At high electron energies the…
The method of QCD sum rules in the presence of the external electromagnetic $F_{\mu\nu}$ field is used to analyze radiative decays of charmed or bottomed mesons such as $D^{\ast}\to D\gamma$ and $B^{\ast}\to B\gamma$, with the…
We observe the radiative decay $D^{*}_{s0}(2317)^{+} \to D_{s}^{*+} \gamma$ for the first time, with a significance exceeding $10$ standard deviations. The signal is found in the continuum $e^+ e^- \to c\bar{c}$ process with the combined…
We calculate $B_{(s)}$, and $D_{(s)}$ to $K^*_0(1430)$ transition form factors, and study semileptonic decays of $B_{(s)}$ and $D_{(s)}\to K_0^*(1430) \bar{\ell}\nu$ based on QCD sum rule. Measuring these semileptonic decays with high…