An observation of the $f_0(1710)$ meson in the $\omega \varphi$ system in the Pion-$Be$ Interaction at Momentum of 29 GeV

Abstract

The charge-exchange reaction ${\pi }^{-}p\to n\omega (783)\varphi (1020)$, $\omega \to {\pi }^{+}{\pi }^{-}{\pi }^0$, $\varphi \to K^{+}{K}^{-}$ 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 $M_{\omega \varphi }$ 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 ${\pi }^{-}p\to n{f}_0(1710)$ the product of branching fractions is found to be: $Br(f_0(1710)\to \pi \pi )\cdot Br(f_0(1710)\to \omega \varphi )=(4.8\pm 1.2)\cdot 10^{-3}$.