Ablikim, M.Achasov, M. N.Adlarson, P.Ahmed, S.Albrecht, M.Aliberti, R.Çetin, Serkant Ali2024-07-182024-07-1820210031-90071079-7114https://doi.org/10.1103/PhysRevLett.127.171801https://hdl.handle.net/11411/7722Using a dataset of 6.32 fb(-1) of e(+)e(-) annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D-s(+) -> tau(+)nu(tau) via tau(+) -> e(+)nu(e)(nu) over bar (tau), and find B-Ds+(->tau+nu tau) = (5.27 +/- 0.10 +/- 0.12) x 10(-2), where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f(Ds+) from lattice quantum chromodynamics calculations or the vertical bar V-cs vertical bar from the CKMfitter group, we extract vertical bar V-cs vertical bar = 0.978 +/- 0.009 +/- 0.012 and f(Ds+) = (251.1 +/- 2.4 +/- 3.0) MeV, respectively. Combining our result with the world averages of BDs+->tau+nu tau and BDs+->mu+nu mu, we obtain the ratio of the branching fractions BDs+->tau+nu tau/BDs+->mu+nu mu = 9.72 +/- 0.37, which is consistent with the standard model prediction of lepton flavor universality.eninfo:eu-repo/semantics/openAccessDecaysArticle2-s2.0-8511897911410.1103/PhysRevLett.127.1718011734739288Q1127Q1WOS:000748548600003