Measurement of e+e- → π+π- cross-section with CMD-2 around ρ-meson

Abstract The cross-section of the process e + e − → π + π − has been measured using about 11 4000 events collected by the CMD-2 detector at the VEPP-2M e + e − collider in the center-of-mass energy range from 0.61 to 0.96 GeV. Results of the pion form factor determination with a 0.6% systematic uncertainty are presented. The following values of the ρ - and ω -meson parameters were found: M ρ =(776.09±0.81) MeV, Γ ρ =(144.46±1.55) MeV, Γ ( ρ → e + e − )=(6.86±0.12) keV, Br( ω → π + π − )=(1.33±0.25)%. Implications for the hadronic contribution to the muon anomalous magnetic moment are discussed.