Semileptonic and rare $B$-meson transitions in a QCD relativistic potential model

P. Colangelo; F. De Fazio; M. Ladisa; G. Nardulli; P. Santorelli; A. Tricarico

doi:doi:10.1007/s100520050446

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2022 Impact factor 4.4

Particles and Fields

Eur. Phys. J. C 8, 81-90
DOI 10.1007/s100529901060

Semileptonic and rare B-meson transitions in a QCD relativistic potential model

P. Colangelo¹ - F. De Fazio¹ - M. Ladisa^1,2 - G. Nardulli^1,2 - P. Santorelli^1,2 - A. Tricarico²

¹ Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Italy
² Dipartimento di Fisica dell'Università di Bari, Italy

Received: 14 September 1998 / Published online: 11 March 1999

Abstract
Using a QCD relativistic potential model, previously applied to the calculation of the heavy meson leptonic constants, we evaluate the form factors governing the exclusive decays $B\to\rho\ell\nu$ , $B\to K^*\gamma$ and $B\to K^*\ell^+\ell^-$ .In our approach the heavy meson is described as a $Q\overline q$ bound state, whose wave function is solution of the relativistic Salpeter equation, with an instantaneous potential displaying Coulombic behaviour at small distances and linear behaviour at large distances. The light vector meson is described by using a vector current interpolating field, according to the Vector Meson Dominance assumption. A Pauli-Villars regularized propagator is assumed for the quarks not constituting the heavy meson. Our procedure allows to avoid the description of the light meson in terms of wave function and constituent quarks, and consequently the problem of boosting the light meson wave function. Assuming as an input the experimental results on $B\to K^*\gamma$ , we evaluate all the form factors describing the $B\to \rho, K^*$ semileptonic and rare transitions. The overall comparison with the data, whenever available, is satisfactory.