Exclusive $B\to K^{\ast \ast }\gamma$ Decays in the QCD LCSR approach

Abstract

We predict contributions of higher $K$-resonances to the radiative rare decays $b\to s\gamma$, in the framework of the QCD sum rules on the light cone (LCSR). Our calculations are restricted to the leading twist-two operators for $K^{\ast }(892)$ and to the asymptotic wave function for the other $K^{\ast \ast }$-mesons. Using experimental data on the semileptonic $\tau \to K^{\ast \ast }{\nu }_{\tau }$ decays, we extract the corresponding decay constants for vector and axial-vector $K^{\ast \ast }$-mesons. We present results for the corresponding branching ratios and compare them with the existing theoretical predictions.

Comments: LaTeX,4 pages. Talk presented at the XXXVIIth Rencontres de Moriond: Electroweak Interactions and Unified Theories, Les Arcs, France, 9-16 March 2002