ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2002, vol. 66, p. -
Study of the process e+e- → π+π -π0 in the energy region √s from 0.98 to 1.38 GeV
The cross section of the process e+e- → π+π-π0 was measured in the Spherical Neutral Detector experiment at the VEPP-2M collider in the energy region √s = 980-1380 MeV. The measured cross section, together with the e +e- → π+π -π0 and ωπ+π- cross sections obtained in other experiments, was analyzed in the framework of the generalized vector meson dominance model. It was found that the experimental data can be described by a sum of ω, φ mesons and two ω′ and ω″ resonances contributions, with masses m ∼ 1490, m ω″ ∼ 1790 MeV and widths Γ ω′ ∼ 1210, Γω′ ∼ 560 MeV. The analysis of the π+π- invariant mass spectra in the energy region √s from 1100 to 1380 MeV has shown that for their description one should take into account the e+e- → ωπ0 →π+π -π0 mechanism also. The phase between the amplitudes corresponding to the e+e- → ωπ and e +e- → ρπ intermediate states was measured for the first time. The value of the phase is close to zero and depends on energy. © 2002 The American Physical Society.