Improved measurement of the branching fraction of Ds plus → μ plus νμ

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ai, X. C.; Aliberti, R.; Amoroso, A.; An, M. R.; An, Q.; Bai, Y.; Bakina, O.; Balossino, I.; Ban, Y.; Batozskaya, V.; Begzsuren, K.; Berger, N.; Berlowski, M.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bianco, E.; Bloms, J.; Bortone, A.; Boyko, I.; Briere, R. A.; Brueggemann, A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chang, J. F.; Chang, T. T.; Chang, W. L.; Che, G. R.; Chelkov, G.; Chen, C.; Chen, Chao; Chen, G.

来源：Physical Review D, 2023, 108(11): 112001.

DOI：10.1103/PhysRevD.108.112001

• D-MESONS
• DECAYS

Using e thorn e- collision data with an integrated luminosity of 7.33 fb-1 collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector operating at the BEPCII collider, the branching fraction of the leptonic decay D thorn s -> mu thorn nu mu is measured to be o0.5294 0.0108stat 0.0085syst thorn %. Based on this, the product of the D thorn s decay constant fD thorn s and the magnitude of the c -> s quark mixing matrix element jVcsj is determined to be fD thorn s jVcsj 1/4 241.8 2.5stat 2.2syst MeV. Using the value of jVcsj given by the global standard model fit, fD thorn s is found to be 248.4 2.5stat 2.2syst MeV. Alternatively, using the value of fD thorn s from a recent lattice quantum chromodynamics calculation, jVcsj is determined to be 0.968 0.010stat 0.009syst.