We report on new measurements of Cabibbo-suppressed semileptonic Ds+ decays using 3.19 fb-1 of e+e-annihilation data sample collected at a center-of-mass energy of 4.178 GeV with the BESIII detector at the BEPCII collider. Our results include branching fractions B(Ds+→K0e+νe)=[3.25±0.38(stat)±0.16(syst)]×10-3 and B(Ds+→K∗0e+νe)=[2.37±0.26(stat)±0.20(syst)]×10-3, which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For Ds+→K0e+νe, we obtain f+(0)=0.720±0.084(stat)±0.013(syst), and for Ds+→K∗0e+νe, we find form-factor ratios rV=V(0)/A1(0)=1.67±0.34(stat)±0.16(syst) and r2=A2(0)/A1(0)=0.77±0.28(stat)±0.07(syst).
Bibliographical noteFunding Information:
The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by National Key Basic Research Program of China under Contract No. 2015CB856700; National Natural Science Foundation of China (NSFC) under Contracts No. 11335008, No. 11425524, No. 11505010, No. 11625523, No. 11635010, No. 11735014, and No. 11775027; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics; Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts No. U1532257, No. U1532258, and No. U1732263; CAS Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003 and No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; Tsung-Dao Lee Institute and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG under Contracts No. Collaborative Research Center CRC 1044 and No. FOR 2359; Istituto Nazionale di Fisica Nucleare, Italy; Koninklijke Nederlandse Akademie van Wetenschappen under Contract No. 530-4CDP03; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology fund; The Swedish Research Council; U.S. Department of Energy under Contracts No. DE-FG02-05ER41374, No. DE-SC-0010118, No. DE-SC-0010504, and No. DE-SC-0012069; University of Groningen and the Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt. This paper is also supported by the Beijing municipal government under Contracts No. KM201610017009, No. 2015000020124G064, and No. CIT&TCD201704047, and by the Royal Society under the Newton International Fellowship Contract No. NF170002.