Has A 125 GeV Pseudoscalar Resonance Been Observed at the LHC?

Abstract

We conjecture that a 125 GeV resonance $\zeta^0$ with $J^{PC}=0^{-+}$ composed of a quark-antiquark state may have been observed at the LHC. The decay modes of this pseudoscalar particle are determined using the non-relativistic quark model. The leading order partial decay widths for the decays of the pseudoscalar quarkonium resonance $\zeta^0\rightarrow \gamma\gamma$ and $\zeta^0\rightarrow gg$ are compared to the standard model Higgs particle decays $H^0\rightarrow \gamma\gamma$ and $H^0\rightarrow gg$. An experimental analysis at the LHC of the observed production cross sections for the $\zeta^0$ and the Higgs particle could distinguish between a heavy quarkonium $\zeta^0$ particle and a light Higgs particle at 125 GeV.