相关论文: Theoretical Approaches to $B \to K^* \gamma$
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 analyzed two form factors $T_1(q^2)$ and $T_2(q^2)$ which enter the $B\to K^* \ell^+ \ell^-$ decay rate and are accessible in the lattice calculations for $B \to K^* \gamma$. The extrapolation to $q^2=0$, necessary for $B\to K^* \gamma$…
The paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in a PQCD approach, we compute the correction to the essential form factor, coming from a single gluon exchange with the spectator. We…
The decay rates for the exclusive B decays $B \rightarrow K \eta_c $ and $B \rightarrow K^* \eta_c$ are calculated in the context of the heavy quark effective theory. We obtain $\Gamma (B \rightarrow K \eta_c )/\Gamma (B\rightarrow K\psi…
We present a detailed study of $B\to K_1(1270) \gamma$ and $B\to K_1(1400) \gamma$ decays. Using the light-cone sum rule technique, we calculate the $B\to K_{1A} (1^3P_1)$ and $B\to K_{1B} (1^1P_1)$ tensor form factors, $T_1^{K_{1A}}(0)$…
We present the results of a lattice QCD calculation of the form factor relevant to B-->K*gamma decay. Our final value, T(0) = 0.24 +/- 0.03(+0.04/-0.01), is obtained in the quenched approximation, and by extrapolating T(q2=0;H-->…
We use the new symmetries in the heavy quark limit to calculate the exclusive B-decays $B \rightarrow K \psi ({\psi}^{\prime})$ and $B \rightarrow K^* \psi ({\psi}^{\prime})$. The estimated decay rates are compared with experimental values.…
Preliminary results are presented on the calculation of the relevant form factor for the radiative decay $\overline{B} \rightarrow K^* \gamma$ We find that the form factor is weakly dependent on the spectator quark mass. We compare the…
We examine the measured rates for the decays $D\to K^{(*)}\ell\nu$, $B\to K^{(*)}\psi^{(\prime)}$ and $B\to K^*\gamma$ in a number of scenarios, in the framework of the heavy quark effective theory. We attempt to find a scenario in which…
We discuss the exclusive radiative decays $B\to K^{*}\gamma$, $B \to\rho\gamma$, and $B\to\omega\gamma$ in QCD factorization within the Standard Model. The analysis is based on the heavy-quark limit of QCD. Our results for these decays are…
We summarise our current results for calculations of the form factors for $B \to K^* \gamma$, and their extrapolation to the physical b-quark mass.
I consider a model for heavy meson decays based on an effective quark-meson Lagrangian. The model is constrained by the known symmetries of QCD in the m_Q -> infinity limit for the heavy quarks, and chiral symmetry in the light quark…
Exclusive radiative B decays, B to K* gamma, K_1(1270) gamma, K_1(1400) gamma and K*_2(1430) gamma, are studied in the framework of a covariant light-front quark model. The tensor form factor T_1(q^2) at q^2=0, which is relevant to the…
We study the (tree-level) weak radiative decays of $B$ mesons. We present a numerical estimate for the inclusive $b \to X_c \gamma (\gamma)$ modes based on the free-quark decay. We then review what is known for the $B \to D^\star \gamma$…
We make use of the information obtained from semileptonic decays of $B$ and $D$ mesons, within an effective lagrangian description based on heavy quark theory and on chiral expansion, to study the radiative decays $B \to K^\star \gamma$ and…
Making use of the measurement of the $B\to K^*\gamma$ branching ratio together with the relations following from the limit of high recoil energy, we obtain stringent constraints on the values of the form-factors entering in heavy-to-light…
A simple relativistic model of heavy-light mesons is applied to the rare decay B -> K* gamma in the standard model. We find Gamma(B -> K* gamma)/Gamma(b -> s gamma)=(17 \pm 4)% and BR(B -> K* gamma)=(4.8 \pm 1.9) \times 10^{-5}(V_cb/.04)^2.…
B meson rare decays ($B\to K(K^{*})l\bar l$ and $B\to K^*\gamma$) are analyzed in the framework of effective field theory of heavy quarks. The semileptonic and penguin type form factors for these decays are calculated by using the light…
The $B \to K^{*}\rho$, $ K^{*}\omega$ decays are useful to determine the CKM angle $\phi_3=\gamma$. Their polarization fractions are also interesting since the polarization puzzle of the $B\to \phi K^*$ decay. We study these decays in the…
The branching fractions of the exclusive decays $B^0\to K^{*0}\gamma$ and $B^+ \to K^{*+}\gamma$ are measured from a sample of $(22.74\pm 0.36)\times 10^6$ $B\bar B$ decays collected with the BABAR detector at the PEP II asymmetric…