Decay $B_s\to \phi \ell^+ \ell^-$ in covariant quark model

TL;DR

This paper calculates form factors for the rare decay $B_s o \phi \, ext{l}^+ ext{l}^-$ using a covariant quark model, providing predictions for branching ratios and polarization observables and comparing them with experimental data.

Contribution

It introduces a comprehensive calculation of form factors in the covariant quark model with infrared confinement for the full kinematic range.

Findings

Predicted branching fractions align with experimental data.

Provided polarization observables for the decay process.

Compared results with other theoretical models.

Abstract

Our article is devoted to the study of the rare $B_s\to \phi \ell^+\ell^-$ decay where $\ell=\mu,\tau$. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the cascade decay $B\to \phi(\to K^+K^-)\ell^+\ell^-$. We compare the obtained results with available experimental data and the results from other theoretical approaches.