Study of dynamics of φ→π+π−π0 decay with CMD-2 detector

Abstract

A study of the φ→π+π−π0 decay mode has been performed using a data sample of about 2.0 million φ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. The following parameters of the φ-meson have been measured: Br(φ→π+π−π0)=0.145±0.009±0.003 and δφ−ω=162±17°. The analysis of the Dalitz plot showed the dominance of the φ→ρπ intermediate mechanism, the limits for the ratio of the direct amplitude of φ→3π to that of φ→ρπ are −0.16<a1<0.11 at 90% C.L. The upper limits for the probabilities of the decay modes φ→π+π−η and direct φ→ργγ have been found for the first time: Br(φ→π+π−η)<3×10−4 and Br(φ→ργγ)<5×10−4 at 90% C.L.