Ablikim, M.Achasov, M. N.Adlarson, P.Ai, X. C.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920231029-8479https://doi.org10.1007/JHEP12(2023)072https://hdl.handle.net/20.500.12713/4807The D-s(+) -> K+K-mu (+)nu(mu) decay is studied based on 7.33 fb(-1)ofe+e-collisiondata collected with the BESIII detector at center-of-mass energies in the range from 4.128to 4.226 GeV. The absolute branching fraction is measured as B(D+s ->phi mu+nu mu) = (2.25 +/- 0.09 +/- 0.07)x10-2, the most precise measurement to date. Combining with the world average of B(D+s ->phi e+nu e), the ratio of the branching fractions obtained is B(D+s ->phi mu+nu mu)B(D+s ->phi e+nu e)=0.94 +/- 0.08, in agreement with lepton universality. By performing a partial wave analysis, the hadronic form factor ratios atq2= 0are extracted, finding rV=V(0)A1(0)= 1.58 +/- 0.17 +/- 0.02andr2=A2(0)A1(0)= 0.71 +/- 0.14 +/- 0.02, where the first uncertainties are statistical and the second are systematic. No significant S-wave contribution fromf0(980)-> K+K-is found. The upper limitB(D+s -> f0(980)mu+nu mu)B(f0(980)-> K+K-)<5.45x10-4is set at 90% credibility leveleninfo:eu-repo/semantics/openAccessBranching FractionCharm PhysicsE(+)-E(-) ExperimentsArticle12WOS:0011332511000012-s2.0-85180703312N/A10.1007/JHEP12(2023)072Q2