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Observation of e+e− Annihilation into the C=+1 Hadronic Final States ρ0ρ0 and ϕρ0

# metadata.dc.description.abstract[].value
We report the first observation of e + e − annihilation into states of positive C parity, namely, ρ 0 ρ 0 and ϕ ρ 0 . The two states are observed in the π + π − π + π − and K + K − π + π − final states, respectively, in a data sample of 225     fb − 1 collected by the BABAR experiment at the Positron-Electron Project II e + e − storage rings at energies near √ s = 10.58     GeV . The distributions of cos ﻿ θ ∗ , where θ ∗ is the center-of-mass polar angle of the ϕ meson or the forward ρ 0 meson, suggest production by two-virtual-photon annihilation. We measure cross sections within the range | cos ﻿ θ ∗ | < 0.8 of σ ( e + e − → ρ 0 ρ 0 ) = 20.7 ± 0.7 ( stat ) ± 2.7 ( syst )     fb and σ ( e + e − → ϕ ρ 0 ) = 5.7 ± 0.5 ( stat ) ± 0.8 ( syst )     fb .

# metadata.dc.source[].value
Articles publicats en revistes (Física Quàntica i Astrofísica)

# metadata.dc.title[].value
Observation of e+e− Annihilation into the C=+1 Hadronic Final States ρ0ρ0 and ϕρ0