Semileptonic Ξ${}_c$ baryon decays in the relativistic quark model

The form factors of the weak Ξ${}_c$→Ξ(Λ) transitions are calculated in the framework of the relativistic quark model based on the quasipotential approach. All relativistic effects including transformations of the baryon wave functions from the rest to moving reference frame and contributions of the intermediate negative energy states are systematically taken into account. The explicit analytic expressions which reliably approximate the momentum transfer q${}^2$ dependence of the form factors in the whole accessible kinematical range are given. The calculated form factors are applied for the evaluation of the semileptonic Ξ${}_c$→Ξℓν${}_{\ell }$ and Ξ${}_c$→Λℓν${}_{\ell }$ (ℓ=e,μ) decay rates, different asymmetry and polarization parameters within helicity formalism. The obtained results are compared with available experimental data and previous calculations.