Precision measurements of the mass, the widths of ψ(3770) resonance and the cross section σ[e+e−→ψ(3770)] at Ecm=3.7724 GeV

M. Ablikim, J.Z. Bai, Y. Ban, J.G. Bian, X. Cai, H.F. Chen, H.S. Chen, H.X. Chen, J.C. Chen, Jin Chen, Y.B. Chen, S.P. Chi (+156 others)
2007 Physics Letters B  
By analyzing the R values measured at 68 energy points in the energy region between 3.650 and 3.872 GeV reported in our previous paper, we have precisely measured the mass, the total width, the leptonic width and the leptonic decay branching fraction of the ψ(3770) to be M_ψ(3770)=3772.4 ± 0.4 ± 0.3 MeV, Γ_ψ(3770)^ tot = 28.6 ± 1.2 ± 0.2 MeV, Γ_ψ(3770)^ee = 279 ± 11 ± 13 eV and B[ψ(3770)→ e^+e^-]=(0.98± 0.04± 0.04)× 10^-5, respectively, which result in the observed cross section σ^
more » ... 3770)]=7.25± 0.27 ± 0.34 nb at √(s)=3772.4 MeV. We have also measured R_ uds=2.121± 0.023 ± 0.084 for the continuum light hadron production in the region from 3.650 to 3.872 GeV.
doi:10.1016/j.physletb.2007.06.074 fatcat:4vgkefqxoje2pj5nvvoxy5q3rq