Test of the $h_1(1830)$ made of $K^{*}\bar{K}^*$ with the $\eta_c\rightarrow \phi K^{*}\bar{K}^{*}$ decay

TL;DR

This paper proposes a new decay process analysis to confirm the existence of an $h_1(1830)$ resonance, showing a clear peak in the $K^*ar{K}^*$ invariant mass distribution, supporting its molecular nature.

Contribution

It introduces a novel reaction channel, $ ext{eta}_c ightarrow ext{phi} K^*ar{K}^*$, to verify the $h_1(1830)$ resonance with detailed invariant mass analysis.

Findings

Peak around 1830 MeV in $K^*ar{K}^*$ distribution

Distinguishable from pure phase space

Supports the molecular nature of the resonance

Abstract

We present a new reaction, complementary to the $J/\psi\rightarrow \eta K^{*0}\bar{K}^{*0}$ from which an $h_1$ resonance with mass around $1830$ MeV was reported from a BESIII experiment. The new reaction is $\eta_c\rightarrow \phi K^*\bar{K}^*$, or $\eta_c(2S)\rightarrow \phi K^*\bar{K}^*$. Using the information from the analysis of $J/\psi\rightarrow \eta K^{*0}\bar{K}^{*0}$, we find that the $K^*\bar{K}^*$ invariant mass distribution for those two $\eta_c$ decays exhibits a clear peak around $1830$ MeV perfectly distinguishable from what one obtains with pure phase space. We suggest the implementation of these reactions to assert the existence of this elusive resonance which, by its nature as a vector-vector molecule with $0^-(1^{+-})$ quantum numbers, only couples to the $K^*\bar{K}^*$ channel.