Decay $$D_s^+ \rightarrow K^{(*)0} \ell ^+\nu _{\ell }$$ in Covariant Quark Model

Semileptonic decay widths of \(D_s^+\) mesons \((D_s^+ \rightarrow K^{(*)0} \ell ^+\nu _{\ell })\) are presented. The required transition form factors are computed in the entire physical range of momentum transfer in the framework of covariant quark model (CQM). We compute the branching fractions incorporating the form factors and obtain the ratio of the partial decay width \(\varGamma (D_s^+ \rightarrow K^0\mu ^+\nu _\mu )/\varGamma (D_s^+ \rightarrow K^0e^+\nu _e) = 0.98\) which is in close resemblance with isospin symmetry.