Reanalysis of rare radiative Ξb−→Ξ−γ decay in QCD

Abstract

The upper limit of the branching ratio of the rare Ξb−→Ξ−γ decay is obtained as BR(Ξb−→Ξ−γ)<1.3×10−4 by the LHCb. In the present work we study this decay within the light cone QCD sum rules employing the Ξb distribution amplitudes. At the first stage, the form factors entering the Ξb−→Ξ−γ decay are obtained. Next, using the results for the form factors the corresponding branching ratio for this decay is estimated to be BR(Ξb−→Ξ−γ)=(4.8±1.3)×10−5. This value lies below the upper limit established by the LHCb collaboration. Our finding for the branching ratio is also compared with the results of the other theoretical approaches existing in the literature. Published by the American Physical Society 2024