New Signature of low mass $Z^{\prime }$ in $J/\psi$ decays

Abstract

We explore a new approach to search for a low-mass $Z^{\prime }$ particle through $J/\psi$ decays by identifying its existence through parity-violating phenomena in the isospin-violating final states of $\Lambda {\overline{\Sigma }}^0$ and the corresponding charge conjugated states of $\overline{\Lambda }{\Sigma }^0$. Our investigation centers on a generation-independent and leptophobic $Z^{\prime }$ with its mass below 10 GeV. Given the present experimental conditions at the Beijing Spectrometer III~(BESIII) and the anticipated opportunities at the Super Tau Charm Factory~(STCF), we conduct Monte-Carlo simulations to predict possible events at both facilities. Notably, we foresee a substantial enhancement in the precision of the lower limit estimation of ${\alpha }_{\text{NP}}$ as well as a reduction in statistical uncertainty with upcoming STCF experiments. Furthermore, it is essential to highlight that a null result in the measurement of ${\alpha }_{\text{NP}}$ would impose stringent constraints, requiring the $Z^{\prime }-q-q$ couplings to be on the order of $10^{-2}$.

Comments: 10 pages, 3 figures, 1 table