The Strong Decay Patterns of the $1^{-+}$ Exotic Hybrid Mesons

TL;DR

This paper calculates decay coupling constants and partial widths of the exotic $1^{-+}$ hybrid mesons using light-cone QCD sum rules, providing predictions to aid experimental searches.

Contribution

It introduces a QCD-based method to compute decay properties of $1^{-+}$ hybrid mesons, differing from phenomenological models and guiding experimental detection strategies.

Findings

Dominant decay modes identified as $ ho ext{ } ext{and} ext{ }f_1$ for isovector state.

Main decay channel for isoscalar partner is $a_1 ext{ } ext{pi}$.

Partial widths differ significantly from previous phenomenological calculations.

Abstract

We calculate the coupling constants of the decay modes $1^{-+}\rightarrow\rho\pi, f_1\pi, b_1\pi, \eta\pi, \eta'\pi, a_1\pi, f_1\eta$ within the framework of the light-cone QCD sum rule. Then we calculate the partial width of these decay channels, which differ greatly from the existing calculations using phenomenological models. For the isovector $1^{-+}$ state, the dominant decay modes are $\rho\pi, f_1\pi$. For its isoscalar partner, its dominant decay mode is $a_1\pi$. We also discuss the possible search of the $1^{-+}$ state at BESIII, for example through the decay chains $J/\psi (\psi')\to \pi_1 +\gamma$ or $J/\psi (\psi')\to \pi_1 +\rho$ where $\pi_1$ can be reconstructed through the decay modes $\pi_1\to \rho\pi\to \pi^+\pi^-\pi^0$ or $\pi_1\to f_1(1285)\pi^0$. Hopefully the present work will be helpful to the experimental establishment of the $1^{-+}$ hybrid meson.