Study of η(1475) and Χ(1835) in Radiative J/ψ Decays to γφ

The decay J/ψ → γγφ is studied using a sample of 1.31 x 10⁹ J/ψ events collected with the BESIII detector. Two structures around 1475 MeV/c² and 1835 MeV/c² are observed in the γφ invariant mass spectrum for the first time. With a fit on the γφ invariant mass, which takes into account the interference between the two structures, and a simple analysis of the angular distribution, the structure around 1475 MeV/c² is found to favor an assignment as the η(1475) and the mass and width for the structure around 1835 MeV/c² are consistent with the X(1835). The statistical significances of the two structures are 13.5σ and 6.3σ, respectively. The results indicate that both η(1475) and X(1835) contain a sizeable ss̅ component.