Measurement of e+e- -> pi+pi- cross section with CMD-2 around rho(770) meson

Abstract

In experiments with the CMD-2 detector at the VEPP-2M electron-positron collider at Novosibirsk about 150000 $e^+e^-\toπ^+π^-$ events were recorded in the center-of-mass energy range from 0.61 up to 0.96 GeV. The result of the pion form factor measurement with a 1.4% systematic error is presented. The following values of the $ρ$-meson and $ρ-ω$ interference parameters were found: $M_ρ=(775.28\pm 0.61\pm 0.20) MeV, Γ_ρ=(147.70\pm 1.29 \pm 0.40) MeV, Γ(ρ\to e^+e^-)=(6.93\pm 0.11\pm 0.10) keV, Br(ω\toπ^+π^-) = (1.32\pm 0.23)%$.