2023/11/30 by M. Ablikim, M. N. Achasov, М. Н. Ачасов +645
Physics and Astronomy · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #High-Energy Particle Collisions Research
paper · pdf · doi:10.1103/physrevd.108.092014
This paper reports the study of Ds+\ensuremath→\ensuremathτ+\ensuremathν via \ensuremathτ+\ensuremath→\ensuremathπ+\ensuremathν_\ensuremathτ using a boosted decision tree method, with 7.33 fb^\ensuremath-1 of e+e^\ensuremath- collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV. The branching fraction of Ds+\ensuremath→\ensuremathτ+\ensuremathν_\ensuremathτ is determined to be (5.44\ifmmode±\else\textpm\fi0.17stat\ifmmode±\else\textpm\fi0.13syst)%. The product of the Ds+ decay constant f_Ds+ and the Cabibbo-Kobayashi-Maskawa matrix element |Vcs| is f_Ds+|Vcs|=(248.3\ifmmode±\else\textpm\fi3.9stat\ifmmode±\else\textpm\fi3.1syst\ifmmode±\else\textpm\fi1.0input) MeV. Combining with the |Vcs| value obtained from the Standard Model global fit or the f_Ds+ from the lattice quantum chromodynamics, we determine |Vcs|=0.993\ifmmode±\else\textpm\fi0.015stat\ifmmode±\else\textpm\fi0.012syst\ifmmode±\else\textpm\fi0.004input and f_Ds+=(255.0\ifmmode±\else\textpm\fi4.0stat\ifmmode±\else\textpm\fi3.2syst\ifmmode±\else\textpm\fi1.0input) 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 Ds+. All results obtained in this work supersede the BESIII previous results based on 6.32 fb^\ensuremath-1 of e+e^\ensuremath- collision data taken at center-of-mass energies between 4.178 and 4.226 GeV.