This paper reports the study of D+s → τ+ν via τ+ → π+ν ̄τ using a boosted decision tree method, with 7.33 fb−1 of e+e− collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV. The branching fraction of D+s →τ+ντ is determined to be (5.44pm0.17stat pm0.13syst)%. The product of the D+s decay constant fD+s and the Cabibbo-Kobayashi-Maskawa matrix element |Vcs| is fD+s |Vcs| = (248.3 3.9stat 3.1syst 1.0input) MeV. Combining with the | Vcs| value obtained from the Standard Model global fit or the fD+s from the lattice quantum chromodynamics, we determine |Vcs| = 0.993 pm 0.015stat pm 012syst pm 004input and fD+s = (255.0 pm 4.0stat pm 3.2syst pm 1.0input) MeV. The first uncertainty is statistical, the second one is systematic and the third one is due to the input parameters, mainly the lifetime of D+s . All results obtained in this work supersede the BESIII previous results based on 6.32 fb−1 of e+e− collision data taken at center-of-mass energies between 4.178 and 4.226 GeV.
Updated measurement of the branching fraction of Ds+→τ+ντ via τ+→π+ν¯τ
Garzia, I.;Gramigna, S.;
2023
Abstract
This paper reports the study of D+s → τ+ν via τ+ → π+ν ̄τ using a boosted decision tree method, with 7.33 fb−1 of e+e− collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV. The branching fraction of D+s →τ+ντ is determined to be (5.44pm0.17stat pm0.13syst)%. The product of the D+s decay constant fD+s and the Cabibbo-Kobayashi-Maskawa matrix element |Vcs| is fD+s |Vcs| = (248.3 3.9stat 3.1syst 1.0input) MeV. Combining with the | Vcs| value obtained from the Standard Model global fit or the fD+s from the lattice quantum chromodynamics, we determine |Vcs| = 0.993 pm 0.015stat pm 012syst pm 004input and fD+s = (255.0 pm 4.0stat pm 3.2syst pm 1.0input) MeV. The first uncertainty is statistical, the second one is systematic and the third one is due to the input parameters, mainly the lifetime of D+s . All results obtained in this work supersede the BESIII previous results based on 6.32 fb−1 of e+e− collision data taken at center-of-mass energies between 4.178 and 4.226 GeV.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.