D Leptonic and semi-leptonic decays from BESIII
The BESIII experiment has taken 2.92/fb of data at sqrt(s) = 3.773 GeV which contains the largest sample of e+e- -> psi(3770) -> DDbar in the world to date. We report the result of our branching fraction measurement of D+ -> mu+ nu based on this sample from which we extract its weak decay constant, f_D+, with the|Vcd| determined from a global Standard Model fit as an input. We also obtain |Vcd| from the measured branching fraction together with a Lattice QCD prediction for f_D+. In addition, we present measurements of D0 -> (K-/pi-) e+ nu, D+ -> KL e+v, and D+ to (omega/phi/K pi) e+ nu decays. Based on analysis of D0 -> (K-/pi-) e+ nu and D+ -> K_L e+ nu, we extract different parameterizations of the form factors together with the CKM matrix elements |Vcs(d)|. These will give a precision test on the LQCD calculation on these form factors and the unitarity of the CKM matrix. Based on analysis of D+ -> K- pi+ e+ nu, we perform a partial wave analysis and in return, we determine the S-wave contribution and its phase, the helicity basis form factors of D+ ->K*(892) e nu based on the SPD model, and we also measure them in a model-independent way. We also report searches for some rare semi-leptonic decays.