相关论文: The Decay $B\to K^*\gamma$ from QCD Sum Rules

We use the new symmetries in the heavy quark limit to calculate the exclusive B-decays $B \rightarrow K^i \psi $ where $K^i$ are higher resonances of K-meson. We then estimate the long distance contributions to $B \rightarrow K^i \gamma $…

We calculate the leading-order matrix element for exclusive decays of $b \to s\gamma$ in the quenched approximation of lattice QCD on a $24^3\times48$ lattice at $\beta=6.2$, using an O(a)-improved fermion action. The matrix element is used…

The large branching ratios for $B \to K\pi$ decays as observed by the CLEO Collaboration indicate that penguin interactions contribute a major part to the decay rates and provide an interference between the Cabibbo-suppressed tree and…

Using $471 \times 10^6 ~B \bar B$ decays recorded with the \babar\ detector at the PEP-II $e^+ e^-$ storage ring, we present the time-dependent \CP\ asymmetry measurement in the radiative penguin decay mode $B^0 \rightarrow K^0_S…

I calculate the form factors describing semileptonic and penguin-induced decays of B mesons into light pseudoscalar mesons. The form factors are calculated from QCD sum rules on the light-cone including contributions up to twist 4,…

In this paper we try to extract the CKM angle $\gamma$ from the new "mixed" system of $B^+ \to \pi^+ K^0$ and $B_d^0 \to \pi^0 K^0$ decays. We also made an update for the constraints on the angle $\gamma$ from the observables $R$ and $A_0$.…

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…

We compute the amplitudes for the two-body decay of $B$ mesons into longitudinally polarized light vector mesons at next-to-leading order in QCD. We give the explicit expressions in QCD factorization for all 34 transitions of a heavy-light…

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…

Within the framework of the perturbative QCD approach, we study the two-body charmless decays $B\to K_1(1270)(K_1(1400))\pi(K)$. We find the following results: (i) The decays $\bar B^0\to K_1(1270)^+\pi^-, K_1(1400)^+\pi^-$ are incompatible…

It has recently been pointed out that the observables of the decay $B^+\to K^+\bar{K^0}$ and its charge conjugate allow us to take into account rescattering effects in constraints on the CKM angle $\gamma$ arising from $B^\pm\to\pi^\pm K$…

We present flavor SU(3) sum rules for $D \to PP$ and $D \to PV$ decay amplitudes, that are valid to second order in symmetry breaking by the strange quark mass spurion. Decay rate sum rules are also computed to this order. Particular…

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…

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…

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 $B\to K^* \gamma$…

We re-examine a recent proposal for obtaining \beta using the measurements of the b -> d penguin decays B_d(t) -> K^0 \kbar and B_s(t) -> \phi K_S, along with a theoretical assumption. We show that there are in fact three assumptions one…

QCD sum rules involving mixed inverse moment integration kernels are used in order to determine the running charm-quark mass in the $\bar{MS}$ scheme. Both the high and the low energy expansion of the vector current correlator are involved…

Weak radiative baryonic B decays $\bar B\to B_1\bar B_2\gamma$ mediated by the electromagnetic penguin process $b\to s\gamma$ are re-examined within the framework of the pole model. The meson pole contribution that has been neglected before…

Finite energy QCD sum rules involving both inverse and positive moment integration kernels are employed to determine the bottom quark mass. The result obtained in the $\bar{\text {MS}}$ scheme at a reference scale of $10\, {GeV}$ is…

The present paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in the PQCD approach developed by Szczepaniak {\it et al.}, we compute the correction, coming from a single gluon exchange with…