Weak decays of $B_s$ mesons to $D_s$ mesons in the relativistic quark model

Abstract

The form factors of weak decays of $B_s$ mesons to ground state $D_s^{(\ast )}$ mesons as well as to their radial $D_s^{(\ast )}(2S)$ and orbital $D_{sJ}^{(\ast )}$ excitations are calculated in the framework of the relativistic quark model based on the quasipotential approach. All relativistic effects, including contributions of intermediate negative-energy states and boosts of the meson wave functions, are consistently taken into account. As a result the form factors are determined in the whole kinematical range without additional phenomenological parametrizations and extrapolations. On this basis semileptonic decay branching fractions are calculated. Two-body nonleptonic $B_s$ decays are considered within the factorization approximation. The obtained results agree well with available experimental data.

Comments: 29 pages, 10 figures, version to be published in Physical Review D