Study of Bs→ℓ+ℓ-γ decays in covariant quark model

We study the rare radiative leptonic decays B_s→^ℓ+ℓ-γ (ℓ=e , μ , τ ) within the Standard Model, considering both the structure-dependent amplitude and bremsstrahlung. In the framework of the covariant confined quark model developed by us, we calculate the form factors characterizing the B_s→γ transition in the full kinematical region of the dilepton momentum squared and discuss their behavior. We provide the analytic formula for the differential decay distribution and give predictions for the branching fractions in both cases: with and without long-distance contributions. Finally, we compare our results with those obtained in other approaches.