D-meson semileptonic decays to pseudoscalars from four-flavor lattice QCD Bazavov, Alexei Gámiz Sánchez, María Elvira We present lattice-QCD calculations of the hadronic form factors for the semileptonic decays D→πℓν, D→Kℓν, and Ds→Kℓν. Our calculation uses the highly improved staggered quark (HISQ) action for all valence and sea quarks and includes Nf=2+1+1 MILC ensembles with lattice spacings ranging from a≈0.12 fm down to 0.042 fm. At most lattice spacings, an ensemble with physical-mass light quarks is included. The HISQ action allows all the quarks to be treated with the same relativistic light-quark action, allowing for nonperturbative renormalization using partial conservation of the vector current. We combine our results with experimental measurements of the differential decay rates to determine |Vcd|D→π=0.2238(11)Expt(15)QCD(04)EW(02)SIB[22]QED and |Vcs|D→K=0.9589(23)Expt(40)QCD(15)EW(05)SIB[95]QED. This result for |Vcd| is the most precise to date, with a lattice-QCD error that is, for the first time for the semileptonic extraction, at the same level as the experimental error. Using recent measurements from BES III, we also give the first-ever determination of |Vcd|Ds→K=0.258(15)Expt(01)QCD[03]QED from Ds→Klν. Our results also furnish new Standard Model calculations of the lepton flavor universality ratios Rμ/eD→π=0.98671(17)QCD[500]QED, Rμ/eD→K=0.97606(16)QCD[500]QED, and Rμ/eDs→K=0.98099(10)QCD[500]QED, which are consistent within 2σ with experimental measurements. Our extractions of |Vcd| and |Vcs|, when combined with a value for |Vcb|, provide the most precise test of second-row Cabibbo-Kobayashi-Maskawa unitarity, finding agreement with unitarity at the level of one standard deviation. 2023-06-29T10:07:38Z 2023-06-29T10:07:38Z 2023-05-31 journal article Bazavov, A. et al. D-meson semileptonic decays to pseudoscalars from four-flavor lattice QCD. Phys. Rev. D 107, 094516. [DOI: 10.1103/PhysRevD.107.094516] https://hdl.handle.net/10481/82944 10.1103/PhysRevD.107.094516 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional American Physical Society