A novel explanation of charmonium-like structure in $e^+e^-\to ψ(2S)π^+π^-$

Abstract

We first present a non-resonant description to charmonium-like structure $Y(4360)$ in the $ψ(2S)π^+π^-$ invariant mass spectrum of the $e^+e^-\to ψ(2S)π^+π^-$ process. The $Y(4360)$ structure is depicted well by the interference effect of the production amplitudes of $e^{+} e^{-} \to ψ(2S) π^+ π^-$ via the intermediate charmonia $ψ(4160)/ψ(4415)$ and direct $e^+e^-$ annihilation into $ψ(2S)π^+ π^-$. This fact shows that $Y(4360)$ is not a genuine resonance, which naturally explains why $Y(4360)$ was only reported in its hidden-charm decay channel $ψ(2S)π^+π^-$ and was not observed in the exclusive open-charm decay channel or $R$-value scan.