Investigating $η^\prime_{1}(1855)$ exotic states in $J/ψ\toη^\prime_{1}(1855)η^{(\prime)}$ decays

Abstract

An analysis of the $J/ψ\to ηη^\primeγ$ decay by the BESIII collaboration claims the observation of an exotic state $η_1(1855)$ with $I^GJ^{PC}=0^+1^{-+}$. To establish its C-parity partner $η^\prime_{1}(1855)$ in the picture of the $K \bar{K}_1(1400)$ molecular state, we propose that $J/ψ\toη^\prime_{1}(1855)η^{(\prime)}$ receives the main contributions from the final state interaction of $KK^*$($K^+ K^{*-}$, $K^- K^{*+}$, $K^0 \bar{K}^{*0}$, and $\bar{K}^0 K^{*0}$). Specifically, $K$ and $K^*$ in $J/ψ\to KK^*$ decays transform as $η^\prime_{1}(1855)η^{(\prime)}$, by exchanging a $K_1(1400)$. We predict ${\cal B}(J/ψ\to η^{\prime}_1(1855)η)=(6.3^{+12.6}_{-3.5})\times 10^{-6}$, and ${\cal B}(J/ψ\to η^{\prime}_1(1855)η^{\prime}) =(6.5^{+6.6}_{-4.6})\times 10^{-6}$, which can be studied in the $J/ψ\to K^*\bar{K}^*η^{(\prime)}$ decays.