Observation of a near-threshold enhancement in the \omega\phi mass spectrum from the doubly OZI suppressed decay J/\psi \to \gamma \omega \phi

TL;DR

This paper reports the observation of a near-threshold enhancement in the omega-phi mass spectrum from J/psi decays, indicating a possible new resonance with specific quantum numbers and measured properties.

Contribution

The study provides the first observation of a threshold enhancement in the omega-phi spectrum from J/psi decays, with detailed analysis of its quantum numbers and branching fractions.

Findings

Enhancement favors J^P = 0^+ quantum numbers.

Mass of the enhancement is approximately 1812 MeV/c^2.

Width of the enhancement is approximately 105 MeV/c^2.

Abstract

An enhancement near threshold is observed in the \omega \phi invariant mass spectrum from the doubly OZI suppressed decays of J/\psi \to \gamma \omega \phi, based on a sample of 5.8 X 10^7 J/\psi events collected with the BESII detector. A partial wave analysis shows that this enhancement favors J^P = 0^+, and its mass and width are M = 1812^{+19}_{-26} (stat) +- 18 (syst) MeV/c^2 and \Gamma = 105+-20 (stat) +- 28$ (syst) MeV/c^2. The product branching fraction is determined to be B(J/\psi\to \gamma X) B(X\to\omega\phi) = (2.61 +- 0.27 (stat) +- 0.65$ (syst)) X 10^{-4}.