X(1870) and $\eta_2(1870)$: Which can be assigned as a hybrid state?

TL;DR

This paper analyzes the mass spectrum and decay modes of X(1870) and η₂(1870), proposing X(1870) as a hybrid meson candidate and η₂(1870) as a conventional quarkonium, with implications for future experimental searches.

Contribution

It distinguishes X(1870) and η₂(1870) as separate resonances and suggests X(1870) is a hybrid state, providing specific decay channels for future experimental validation.

Findings

X(1870) is a good hybrid candidate.

η₂(1870) is identified as η₂(2¹D₂) quarkonium.

Future searches should focus on specific decay channels.

Abstract

The mass spectrum and strong decays of the X(1870) and $\eta_2(1870)$ are analyzed. Our results indicate that X(1870) and $\eta_2(1870)$ are the two different resonances. The narrower X(1870) seems likely a good hybrid candidate. We support the $\eta_2(1870)$ as the $\eta_2(2^1D_2)$ quarkonium. We suggest to search the isospin partner of X(1870) in the channels of $J/\psi\rightarrow\rho f_0(980)\pi$ and $J/\psi\rightarrow\rho b_1(1235)\pi$ in the future. The latter channel is very important for testing the hybrid scenario.