Prediction of the D s * Width from a Calculation of its Radiative Decay in Full Lattice QCD

We determine the rate for D-s* -> D-s gamma for the first time from lattice QCD and include the full effect of u, d, and s sea quarks. The valence quarks are implemented by using the highly improved staggered quark formalism and we normalize the vector current nonperturbatively. We obtain M(D-s*) - M(D-s) of 148(4) MeV, in good agreement with experiment. The value of the decay constant of the D-s* we find to be 274(6) MeV, so that f(Ds)*/f(Ds) = 1.10(2). For the radiative decay, we find Gamma(D-s* -> D-s gamma) = 0.066(26) keV. Given the experimental branching fraction for this decay, we predict a total width for the D-s* of 0.070(28) keV, making this the longest-lived charged vector meson. We also determine the branching fraction for D-s* leptonic decay to be 3.4(1.4) x 10(-5), putting it within the range of possible detection at next-generation flavor factories.