Study of the Process e+e–→π+π– in the Energy Region 400 < <RADICAL><RADICAND>s</RADICAND></RADICAL>< 1000 MeV.

The cross section of the process e⁺e^- ↵ π⁺π^- was measured in the spherical neutral detector experiment at the VEPP-2M collider in the energy region 400 < √s < 1000 MeV. This measurement was based on about 12.4 ⊗ 10⁶ selected collinear events, which include 7.4 ⊗ 10⁶ e⁺e^- ↵ e⁺e^-, 4.5 ⊗ 10⁶ e⁺e^- ↵ π⁺π^-, and 0.5 ⊗ 10⁶ e⁺e^- ↵ μ⁺μ^- selected events. The systematic uncertainty of cross section determination is 1.3%. The r-meson parameters were determined as m_ρ = 774.9 ± 0.4 ± 0.5 MeV, Γ_ρ = 146.5 ± 0.8 ± 1.5 MeV, and σ(ρ ↵ π⁺π^-) = 1220 ± 7 ± 16 nb and the parameters of the G-parity suppressed decay ω π⁺π^- as σ(ω ↵ π⁺π^-) = 29.9 ± 1.4 ± 1.0 nb and Φ_ρω = 113.5 ± 1.3 ± 1.7°. [ABSTRACT FROM AUTHOR]