Narrow Results

The radiative leptonic decays D_s → μν_μγ and D → μν_μγ are investigated at the tree level within the relativistic independent quark model based on the confining potential in the scalar–vector harmonic form. The branching ratios for these decays in the vanishing lepton mass limit are obtained as ℬr(D_s → μν_μγ) = 4.94×10^-4 and ℬr(D → μν_μγ) = 3.34×10^-5, which includes the contributions of the internal bremsstrahlung and structure dependent diagrams at the level of the quark constituents. Finally, the photon energy spectra as predicted here is found to be symmetric about the peak value of the photon energy at .