The decay properties of two- and three- gluon glueballs

We previously studied the decay properties of two- and three-gluon glueballs using the Fierz rearrangement method and obtained their relative branching ratios in Ref.~\cite{Tan:2026uue}. In this work, we extend and develop this analysis by providing a more complete treatment of two-gluon glueball decays and by considering the tensor and pseudotensor states with $J^{PC}=2^{++}$ and $2^{-+}$. We also perform an independent QCD sum rule analysis of the $0^{++}$ two-gluon glueball decay. The consistency between the two approaches provides a useful check of the Fierz analysis. Our results support a sizable gluon component in the $f_0(1710)$ and favor the $0^{-+}$ glueball interpretation of the $\eta (2370)$. For the tensor glueball, the vector–vector ($VV$) decay channels, especially $K^{\ast }(892){\bar{K}}^{\ast }(892)$, are found to be favorable for experimental searches. We also study three-gluon glueballs with $J^{PC}=0^{++}$ and $1^{+-}$ and identify several potentially favorable three-meson decay channels, including $\pi \pi \omega$ and $K\bar{K}\varphi$. These results provide possible guidance for future experimental searches for glueball states.