相关论文: A study on the rare radiative decay $B_c \to D_s^*…

A search for the rare decay of a $B^{0}$ or $B^{0}_{s}$ meson into the final state $J/\psi\gamma$ is performed, using data collected by the LHCb experiment in $pp$ collisions at $\sqrt{s}=7$ and $8$ TeV, corresponding to an integrated…

We report on recent progress in studying two aspects of $B$ physics, in which penguin amplitudes play an important role: (1) Bounds on penguin pollution in $B^0(t) \to \pi^+\pi^-$ constraining CKM parameters, and a lower bound on $B^0 \to…

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 apply the perturbative QCD factorization theorem developed recently for nonleptonic heavy meson decays to the radiative decay $B\to K^*\gamma$. In this formalism the evolution of the Wilson coefficients from the $W$ boson mass down to…

The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix. It is shown that bounds on $\gamma$ can also be obtained from the time evolution of…

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…

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…

The radiative decay $\Lambda_{b}^{0} \to \Lambda \gamma$ is observed for the first time using a data sample of proton-proton collisions corresponding to an integrated luminosity of $1.7\,fb^{-1}$ collected by the LHCb experiment at a…

The contribution to the decay $b\to s \gamma$ in the Minimal Supersymmetric Standard Model with radiative electroweak breaking is presented. The impact of a detection of this inclusive decay at the SM level is discussed. Results for other…

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…

We have searched for the baryon-containing radiative penguin decays B^- -> \Lambda p-bar \gamma and B^- -> \Sigma^0 p-bar \gamma, using a sample of 9.7 million BBbar events collected at the \Upsilon(4S) with the CLEO detector. We find no…

At LHC a large number of b-flavored baryons will be produced. In this note we propose new baryon modes to determine the photon helicity of the penguin transition $b \to s \gamma$. The decay $\Lambda_b \to \Lambda \gamma$ has the drawback…

A general parametrization of the $B^+\to\pi^+ K^0$ and $B_d^0\to\pi^- K^+$ decay amplitudes is presented. It relies only on the isospin symmetry of strong interactions and the phase structure of the Standard Model and involves no…

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…

We calculate to the leading twist 2 accuracy the rate for the decay $ B_{u} \rightarrow l \nu \gamma $ using the light cone QCD sume rules. We find $ Br( B_{u} \rightarrow l \nu \gamma) \simeq 2 \cdot 10^{-6} $. The results are used to test…

A completely general parametrization of the time-dependent decay rates of the modes $B_s\to J/\psi K_S$ and $B_d\to J/\psi K_S$ is given, which are related to each other through the $U$-spin flavour symmetry of strong interactions. Owing to…

Rare radiative decay $\phi\to\eta\pi^0\gamma$ was studied with SND detector at {VEPP-2M} electron-positron collider and its branching ratio was measured: $B(\phi\to\eta\pi^0\gamma)=(0.88\pm0.14\pm0.09)\cdot 10^{-4}$. Significant…

With heavy quark limit and hierarchy approximation $\lambda_{QCD}\ll m_D\ll m_B$, we analyze the $B\to D^0\bar D^0$ and $B_s\to D^0\bar D^0$ decays, which occur purely via annihilation type diagrams. As a roughly estimation, we calculate…

We analyze the radiative leptonic $B_c$ decay mode: $B_c \to \ell \nu \gamma$ ($\ell=e, \mu$) using a QCD-inspired constituent quark model. The prediction: ${\cal B}(B_c \to \ell \nu \gamma)\simeq 3 \times 10^{-5}$ makes this channel…