Measurement of thee ⁺ e ⁻→π ⁺ π ⁻ π ⁰ ande ⁺ e ⁻→ωπ ⁺ π ⁻ reactions in the energy interval 1350–2400 MeV

Abstract

The cross sections fore ⁺ e ⁻→π ⁺ π ⁻ π ⁰ ande ⁺ e ⁻→ωπ ⁺ π ⁻ have been measured in the 1.35 ≦$\sqrt s$ ≦2.4 GeV range from 1900 nb⁻¹ collected by DM2 at DCI. The second process proceeds via a resonant state at ≈- 1660 MeV/c², ≈- 280 MeV/c² wide. The first one is larger than a VDM extrapolation from the ω-ϕ peaks and, although does not show any clear structure, is compatible with the presence of the above resonance.