An Observation of the $f_0(1710)$ Meson in the $ωϕ$ System in the Pion-$Be$ Interaction at Momentum of 29 GeV

The charge-exchange reaction π^-p → n ω(783)ϕ(1020), ω→π^+π^-π^0, ϕ→ K^+K^- is studied with the upgraded VES facility (U-70, Protvino) in the interaction of a 29 GeV pion beam with a beryllium target. The distribution over the invariant mass of the system M_ωϕ shows a near-threshold signal. A partial wave analysis reveals that the scalar state (J^PC=0^++) dominates in this mass region. The observed signal can be described with a contribution of the known resonance f_0(1710). Using OPE approximation for the reaction π^-p → n f_0(1710) the product of branching fractions is found to be: Br(f_0(1710)→ππ)· Br(f_0(1710)→ωϕ) = (4.8 ± 1.2) · 10^-3.