Form factors for rare decays $B\to (\pi ,\rho ,K,K^{\ast })l^{+}{l}^{-}$ in quark model

Abstract

Hadronic matrix elements of the vector, axial-vector and tensor currents relevant for exclusive rare decays $B\to (\pi ,\rho ,K,K^{\ast })l^{+}{l}^{-}$ induced by the quark transition $b\to d,s$ are analysed using dispersion formulation of the light-cone constituent quark model. The form factors in the decay region are expressed as relativistic double spectral representations through the light-cone wave functions of the initial and final mesons. These form factors are shown to have the correct scaling properties in the limit of heavy-to-heavy and heavy-to-light quark transitions in accordance with QCD. The dependence on the quark-model parameters is studied.

Comments: 8 pages, revtex, 1 figure