Prediction of charmoniumlike structures in the hidden-charm di-eta decays of higher charmonia

Abstract

Considering the situation that a single chiral partilce, $\eta$, is initially emitted, we study the hidden-charm di-eta decays of charmoniumlike state $Y(4660)$ and the predicted charmonium $\psi (4790)$, i.e., $Y(4660)/\psi (4790)\to J/\psi \eta \eta$ through the inetermediates, $\eta \left[D^{(\ast )}{\bar{D}}^{(\ast )}\right]$ and/or $\eta \left[D_s^{+(\ast )}{D}_s^{-(\ast )}\right]$, and answer to the important question whether there exist isoscalar charmoniumlike structures in the $D^{(\ast )}{\bar{D}}^{(\ast )}$ and/or $D_s^{+(\ast )}{D}_s^{-(\ast )}$ channels. Our results predict that there will be enhancement structures near $D{\bar{D}}^{\ast }$, $D^{\ast }{\bar{D}}^{\ast }$ and $D_s{\bar{D}}_s^{\ast }$ thresholds for $Y(4660)$ and near $D^{\ast }{\bar{D}}^{\ast }$, $D_s{\bar{D}}_s^{\ast }$ and $D_s^{\ast }{\bar{D}}_s^{\ast }$ thresholds for $\psi (4790)$ in the $M_{\max }(J/\psi \eta )$ distributions of $Y(4660)/\psi (4790)\to \eta \eta J/\psi$, respectively. These peaks are accessible at future experiments, especially BESIII, Belle, BaBar and forthcoming BelleII.

Comments: 6 pages, 1 table and 5 figures. More discussions added. Accepted by Journal of Physics G: Nuclear and Particle Physics