Measurement of the e⁺e^- →π⁺π^- process cross section with the SND detector at the VEPP-2000 collider in the energy region 0.525<√(s)<0.883 GeV

2020/04/30 by SND Collaboration, M. N. Achasov, A. A. Baykov +34 · 1 citation
Physics and Astronomy · #hep-ex

paper · pdf · doi:10.1007/jhep01(2021)113

arxiv created 2020/11/26 · arxiv updated 2021/02/24

Abstract

The cross section of the process e⁺ e^-→π⁺π^- has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000 e⁺e^- collider VEPP-2000 in the energy region 525 <√[]s <883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb^-1. The systematic uncertainty of the cross section determination is 0.8 % at √(s)>0.600 GeV. The ρ meson parameters are obtained as m_ρ= 775.3± 0.5± 0.6 MeV, Γ_ρ= 145.6± 0.6± 0.8 MeV, B_{ρ→ e⁺ e^-}× B_{ρ→π⁺π^-} = (4.89± 0.02± 0.04)× 10^-5, and the parameters of the e⁺ e^-→ω→π⁺π^- process, suppressed by G-parity, as B_{ω→ e⁺ e^-}× B_{ω→π⁺π^-}= (1.32± 0.06± 0.02)× 10^-6 and ϕ_ρω = 110.7± 1.5±1.0 degrees.

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