Abstract
Considerable advances have been made over the past decades in experimentally studying the decays of hadrons containing heavy quarks. In particular, branching ratios were measured for exclusive semileptonic and rare decays of both beauty and charmed mesons and baryons. The results obtained in studying the rare semileptonic decays \(\Xi_{b}^{-}\rightarrow\Xi^{-}l^{+}l^{-}\) , and \(\Xi_{b}^{0}\rightarrow\Lambda l^{+}l^{-}\) , are given in the present article. Form factors that parametrize the weak-current matrix elements between baryon states are calculated in the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The differential and total decay widths, as well as asymmetries and polarization characteristics of the decays, are calculated on the basis of the helicity formalism. The calculations are performed both with and without the inclusion of the long-range contribution of charmonium vector resonances to Wilson coefficients. Predictions for decay widths are obtained for three lepton generations.
