Semileptonic decays of D(s ) mesons

A symmetry-preserving continuum approach to meson bound states in quantum field theory, employed elsewhere to describe numerous π - and K -meson electroweak processes, is used to analyze leptonic and semileptonic decays of D(s ) mesons. Each semileptonic transition is conventionally characterized by the value of the dominant form factor at t =0 and the following results are obtained herein: f+Ds→K(0 )=0.673 (40 ); f+D→π(0 )=0.618 (31 ) and f+D→K(0 )=0.756 (36 ). Working with the computed t -dependence of these form factors and standard averaged values for |Vc d|, |Vc s|, one arrives at the following predictions for the associated branching fractions: BDs+→K0e+νe=3.31 (33 )×10-3, BD0→π-e+νe=2.73 (22 )×10-3, and BD0→K-e+νe=3.83 (28 )%. Alternatively, using the calculated t -dependence, agreement with contemporary empirical results for these branching fractions requires |Vc d|=0.221 (9 ), |Vu s|=0.953 (34 ). With all D(s ) transition form factors in hand, the nature of SU(3)-flavor symmetry breaking in this array of processes can be analysed; and just as in the π -K sector, the magnitude of such effects is found to be determined by the scales associated with emergent mass generation in the Standard Model, not those originating with the Higgs mechanism.