Studies of Charmonium at BESIII

TL;DR

This paper reports on various charmonium decay studies at BESIII using large datasets, setting upper limits on some rare decays and observing specific decay channels, thereby enhancing understanding of charmonium structure and symmetry violations.

Contribution

The study provides new measurements and limits on charmonium decays, including observations of certain transitions and searches for symmetry-violating decays, expanding knowledge of charmonium properties.

Findings

Observed $ o o o o$ $ o$ decays.

Set upper limits on isospin and C-parity violating decays.

Measured specific transition rates.

Abstract

Based on $\psi(3686)$ decays of 106 million, the 1.31 billion J/psi events and a data sample of $\psi(3770)$ with $2.9~fb^{-1}$ integrated luminosity, many analyses are performed. Exclusively baryonic decays of the $\psi(3770)$, the radiative transition $\psi(3770)\to\gamma\eta_c(2S)$, the $\psi(3770)$ transition to $\chi_{cJ}$, isospin violation decay $\chi_{c0,2}\to\pi^0\eta_c$, the $C-$parity violation decays $J/\psi\to\gamma\gamma,\gamma\phi$ are searched for, but no significant signals are observed, and upper limits are set for these decays. The decays of $\psi(3770)\to\gamma\chi_{c1}$ and $J/\psi\to\pi^0\phi$ signals are observed. These measurements provide more information on the charmonium structure, and the isospin and $C$-parity violation in the charmonium decays.