The nonfactorizable QED correction to the \(\overline{B}_{s}\) \({\rightarrow }\) \(D_{s}^{(*)} {\ell } \bar{\nu }_{\ell }\) decays

Abstract

Considering the nonfactorizable QED corrections, the branching ratios and ratios of branching ratios \(R(D_{s}^{({*})})\) for the semileptonic \(\overline{B}_{s}\) \({\rightarrow }\) \(D_{s}^{(*)} {\ell } \bar{\nu }_{\ell }\) decays are reevaluated. It is found that (a) the QED contributions can enhance the branching ratios and reduce the ratios \(R(D_{s}^{({*})})\). (b) The SU(3) flavor symmetry holds basically well in the ratios R(D)-\(R(D^{*})\) for the semileptonic charmed \(\overline{B}_{u,d,s}\) decays. (c) The current theoretical uncertainties of branching ratios \(\mathcal{B}(\overline{B}_{s} {\rightarrow } D_{s}^{*} {\ell } \bar{\nu }_{\ell })\) from the form factors are very large.