相关论文: The Rare Decay $B\to K^{\ast}\gamma$: A More Preci…
We show that the exclusive decay $B\rightarrow K^{\ast}\gamma$ can be related to the semileptonic decay $B\rightarrow\rho e\bar{\nu}$ using heavy-quark symmetry and $SU(3)$ flavor symmetry. A direct measurement of the $q^{2}$-spectrum for…
The exclusive rare decay $B \ra K^\ast \gamma$ takes place in a region of maximum recoil, $q^{2}=0$, posing a problem for nonrelativistic quark models which are usually thought to be most reliable at zero recoil. The Bauer--Stech--Wirbel…
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.…
The method of calculating electroweak decay matrix elements between heavy-heavy and heavy-light meson states is developed in the framework of relativistic quark model based on the quasipotential approach in quantum field theory. This method…
The branching fractions of the rare weak $B\to \pi l^+l^-(\nu\bar\nu)$ and $B\to\rho l^+l^-(\nu\bar\nu)$ decays are calculated in the framework of the relativistic quark model based on the quasipotential approach. The form factors…
Exclusive semileptonic B decays to radially excited charmed mesons and rare radiative B decay to the orbitally excited tensor K_2^*(1430) meson are investigated in the framework of the relativistic quark model based on the quasipotential…
The exclusive semileptonic $B\to \pi(\rho) e\nu$ decays are studied in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. The large recoil momentum of the final $\pi(\rho)$ meson…
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 +…
We review some selected rare B decays calculated in next-to-leading order accuracy in the Standard Model (SM). These include the radiative decays $B \to (X_s,K^*,\rho)\gamma$ and the semileptonic decays $B \to (X_s,K,K^*) \ell^+ \ell^-$,…
We describe two recent theoretical calculations of the $B \to K^* \gamma$ decay. The first method is based on an effective lagrangian incorporating chiral symmetry for the light degrees of freedom and the heavy quark spin-flavor symmetries…
We reexamine contributions of higher $K$-resonances to the radiative rare decays $b\rar s\gamma$ in the limit where both $b$- and $s$-quark are considered heavy. Using the non-relativistic quark model, and the form factor definitions…
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 $…
I discuss recent progress in our understanding of exclusive rare and semileptonic decays. I show the impact of HQET when combined with the predictions in the Large Energy Limit of QCD, focusing first on applications to $B\to…
The exclusive rare radiative $B$-decays are studied in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. The large recoil momentum of the final vector meson allows for the expansion…
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…
Experimental era of rare $B$-decays started with the measurement of $B \to K^* \gamma$ by CLEO in 1993, followed two years later by the measurement of the inclusive decay $B \to X_s \gamma$, which serves as the standard candle in this…
We compute the branching fraction of the decays $B \to K \nu \bar\nu$ and $B \to K^* \nu \bar\nu$ in the Standard Model. We also comment on the experimental difficulties and procedures to detect such modes at B factories.
The b --> s gamma transition proceeds by a loop ``penguin'' diagram. It may be used to measure precisely the couplings of the top quark and to search for the effects of any new particles appearing in the loop. We present a preliminary…
We report recent results in rare B decays. Our focus will be on b -> d gamma and b -> s l^+ l^- transitions. We discuss their impact on the CKM phenomenology and their role within our search for new physics. In particular, we analyse the…
We investigate the exclusive rare semileptonic decays: $B(B_c)\to K(D_{(s)})l\bar{l}/\Sigma\nu_l\bar{\nu_l}$ ($l=\mu, \tau$) in the framework of relativistic independent quark (RIQ) model based on an average flavor independent confining…