More hidden heavy quarkonium molecules and their discovery decay modes

Abstract

To validate the molecular description of the observed ${Z}_{b}(10610)/{Z}_{b}(10650)$ and ${Z}_{c}(3900)/{Z}_{c}(4025)$, it is valuable to investigate their counterparts, denoted as ${Z}_{QV}^{(\ensuremath{'})}$ in this work, and the corresponding decay modes. In this work, we present an analysis of the ${Z}_{QV}^{(\ensuremath{'})}$ using flavor symmetry. We also use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths for the isospin conserved channels ${Z}_{QV}^{(\ensuremath{'})}\ensuremath{\rightarrow}{\ensuremath{\eta}}_{Q}V$. The predicted partial widths are of an order of MeV for ${Z}_{QV}\ensuremath{\rightarrow}{\ensuremath{\eta}}_{Q}V$ which corresponds to branching ratios of the order ${10}^{\ensuremath{-}2}\ensuremath{\sim}{10}^{\ensuremath{-}1}$. For ${Z}_{QV}^{\ensuremath{'}}\ensuremath{\rightarrow}{\ensuremath{\eta}}_{Q}V$, the partial widths are a few hundreds of keV and the branching ratios are about $1{0}^{\ensuremath{-}3}$. Future experimental measurements can test our predictions on the partial widths and thus examine the molecule description of heavy quarkoniumlike exotic states.