Partial Wave Analysis of $J/ψ\to γ(K^{\pm}K_S^0π^{\mp})$

Abstract

BES data on $J/ψ\to γ(K^{\pm} K_S^0 π^{\mp})$ are presented. There is a strong peak due to $η(1440)/ι$, which is fitted with a Breit-Wigner amplitude with $s$-dependent widths for decays to $K^*K$, $κK$, $ηππ$ and $ρρ$; $κ$ refers to the $Kπ$ S-wave. At a $K\bar{K}π$ mass of $\sim 2040$ MeV, there is a second peak with width $\sim 400$ MeV; $J^P = 0^-$ is preferred over $1^+$ and $2^-$ respectively by 5.2 and 6.8 standard deviations. It is a possible candidate for a $0^-$ $s\bar sg$ hybrid partner of $π(1800)$.