Speaker
Description
BESIII has collected data samples corresponding to luminosities of 2.93 fb-1 and 3.19 fb-1 at center-of-mass energies of 3.773 and 4.178 GeV, respectively. In addition, data samples with a luminosity of about 3 fb-1 at center-of-mass energies between 4.19 and 4.23GeV are used to study Ds decays in some analyses. We report recent measurements that include the decays D(s)+ -> l+ nu (l=mu, tau), D0(+)-> Kbar(pi) l+ nu(l=e, mu), D0(+) -> a0(980) e+ nu, D+ -> K1(1270) e+ nu, D(s) + -> eta(`) e+ nu, Ds -> K(*)0 e+ nu, and Ds -> phi e+ nu. The first searches for Ds -> gamma e+ nu and Ds -> p pbar e+ nu are also presented. From these analyses, the decay constants f_D(s), the semileptonic form factors f^P_+(0) [P=K, pi, eta(‘)], the CKM matrix elements |Vcs| and |Vcd| are determined precisely. These results can verify the LQCD calculations of fD(s)+, f^P_+(0) and the CKM matrix unitarity. Precision tests of lepton-flavor universality are also made via D(s)+ -> l+ nu and D0(+) -> Kbar(pi) l+ nu, decays.
