On the nature of the $\pi_2(1880)

TL;DR

This paper investigates the decay properties of the $ ext{pi}_2(1880)$ meson using two models, concluding it is likely a conventional quark-antiquark state rather than a hybrid, based on decay pattern analysis.

Contribution

It provides a comparative analysis of decay patterns in the $^3P_0$ and flux-tube models, clarifying the nature of the $pi_2(1880)$ meson as a conventional $2 ^1D_2$ state.

Findings

Decay patterns differ significantly between the $2 ^1D_2$ meson and the hybrid.

Experimental evidence favors the $pi_2(1880)$ as a conventional meson.

The hybrid mixture hypothesis is discussed but less supported.

Abstract

The strong decays of the $\pi_2(1880)$ as the $2 ^1D_2$ quark-antiquark state are investigated in the $^3P_0$ model and the flux-tube model, respectively. The results are similar in the two models. It is found that the decay patterns of the conventional $2 ^1D_2$ meson and the $2^{-+}$ light hybrid are very different, and the experimental evidence for the $\pi_2(1880)$ is consistent with it being the conventional $2 ^1D_2$ meson rather than the $2^{-+}$ light hybrid. The possibility of the $\pi_2(1880)$ being a mixture of the conventional $q\bar{q}$ and the hybrid is discussed.