Search for a muonphilic scalar $X_0$ or vector $X_1$ via $J/\ddot{I}ˆ\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}+\mathrm{invisible}$ decays at BESII

Abstract

A light scalar $X_0$ or vector $X_1$ particles have been introduced as a possible explanation for the $(g-2{)}_{\hat{I}}¼$ anomaly and dark matter phenomena. Using $(8.998\pm 0.039)\times 10^9$ $\jpsi $ events collected by the BESIII detector, we search for a light muon philic scalar $X_0$ or vector $X_1$ in the processes $J/\ddot{I}ˆ\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}{X}_{0,1}$ with $X_{0,1}$ invisible decays. No obvious signal is found, and the upper limits on the coupling $g_{0,1}^{\prime }$ between the muon and the $X_{0,1}$ particles are set to be between $1.1\times 10^{-3}$ and $1.0\times 10^{-2}$ for the $X_{0,1}$ mass in the range of $1<M(X_{0,1})<1000$ MeV$/c^2$ at 90$\%$ confidence level.

9 pages 7 figures