With the recent measurements of purely leptonic D(s)+ decays and semileptonic D decays in conjunction with decay constants fD(s)+ and form factors f+π(K)(0) calculated in LQCD, we extract the magnitudes of Vcd and Vcs to be ∣Vcd∣=0.218±0.005 and ∣Vcs∣=0.987±0.016. Compared to those given in PDG2013, the precisions of these newly extracted ∣Vcd∣ and ∣Vcs∣ are improved by more than 2.0 and 1.5 factors, respectively. With the newly extracted ∣Vcd∣ and ∣Vcs∣ together with other CKM matrix elements given in PDG2013, we check the unitarity of the CKM matrix, which are ∣Vud∣2+∣Vcd∣2+∣Vtd∣2=0.997±0.002, ∣Vus∣2+∣Vcs∣2+∣Vts∣2=1.027±0.032 and ∣Vcd∣2+∣Vcs∣2+∣Vcb∣2=1.023±0.032.
@article{arxiv.1409.1068,
title = {Determinations of quark mixing matrix elements $|V_{cd}|$ and $|V_{cs}|$ from leptonic and semileptonic $D$ Decays},
author = {G. Rong and Y. Fang and H. L. Ma},
journal= {arXiv preprint arXiv:1409.1068},
year = {2014}
}