Ablikim, M.Achasov, M. N.Adlarson, P.Aliberti, R.Amoroso, A.An, M. R.Çetin, Serkant Ali2024-05-192024-05-1920232470-00102470-0029https://doi.org10.1103/PhysRevD.108.092003https://hdl.handle.net/20.500.12713/5828Precision measurements of the semileptonic decays D-s(+) -> eta e(+) nu(e) and D-s(+) -> eta'e(+) nu(e) are performed with 7.33 fb(-1) of e(+) e(-) collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector. The branching fractions obtained are B(D-s(+) -> eta e(+) nu(e)) = (2.255 +/- 0.039(stat) +/- 0.051(syst)) % and B(D-s(+) -> eta'e(+) nu(e)) = (0.810(stat) +/- 0.024(syst))%. Combining these results with the B(D+ -> eta e(+) nu(e)) and B(D+ -> eta'e(+) nu(e)) obtained from previous BESIII measurements, the eta - eta' mixing angle in the quark flavor basis is determined to be phi(P) = (40.0 +/- 2.0(stat) +/- 0.6(syst))degrees. Moreover, from the fits to the partial decay rates of D-s(+) -> eta e(+) nu(e) and D-s(+) -> eta'e(+) nu(e), the products of the hadronic transition form factors f(+)(eta()'()) (0) and the modulus of the c -> s Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cs vertical bar are determined by using different hadronic transition form factor parametrizations. Based on the two-parameter series expansion, the products f(+)(eta) (0) vertical bar V-cs vertical bar = 0.4519 +/- 0.0071(stat) +/- 0.0065(syst) and f(+)eta'(0) vertical bar V-cs vertical bar = 0.525 +/- 0.024(stat) +/- 0.009syst are extracted. All results determined in this work supersede those measured iPrecisionn the previous BESIII analyses based on the 3.19 fb(-1) subsample of data at 4.178 GeV.eninfo:eu-repo/semantics/openAccessDecaysTimeTofArticle1089WOS:0011178632000062-s2.0-85181001042N/A10.1103/PhysRevD.108.092003Q1