Study of the decayf1(1285)→ρ0(770)γ

The decayf1(1285)→ρ0(770)γ was studied at VES spectrometer of IHEP. Clear signal off1(1285) is seen in the effective mass spectrum of the π+π−γ system in the reaction π−γN→π+π−π−γN at the momentum\(P_{\pi ^ - } = 37 GeV/c\). The branching fraction of decayf1(1285)→ρ0(770)γ has been found to be $$BR(f_1 (1285) \to \rho ^0 (770)\gamma ) = (2.8 \pm 0.7(stat) \pm 0.6(syst)) \cdot 10^{ - 2} .$$ The ratio of the helicity amplitudes for ρ0 meson in its rest frame was determined by the analysis of angular distributions: $$\rho _{00} /\rho _{11} = 3.9 \pm 0.9(stat) \pm 1.0(syst).$$