ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2000, vol. 491, p. 81-89
Observation of the φ → π+π-π+π- decay
Using 11.6 pb-1 of data collected in the energy range 0.984-1.06 GeV by CMD-2 at VEPP-2M, the cross section of the reaction e+e- → π+π-π+π- has been studied. For the first time an interference pattern was observed in the energy dependence of the cross section near the φ meson. The branching ratio of the φ → π+π-π+π- decay double suppressed by the G-parity and OZI rule is measured Br(φ → π+π-π+π-) = (3.93 ± 1.74 ± 2.14) x 10-6. The upper limits have been placed for the decays φ → π+π-π+π-π0 and ηπ+ Br(φ → π+π-π+π-π0) < 4.6 x 10-6 90% CL, Br(φ → ηπ+π-) < 1.8 x 10-5 90% CL. (C) 2000 Published by Elsevier Science B.V.