Light meson decays at BESIII

TL;DR

This paper reviews recent advances in light meson spectroscopy at BESIII, highlighting new decay observations, searches for CP violation, rare decay investigations, and precise measurements of $ ext{eta}^ ext{' }$ decay branching fractions.

Contribution

It presents new experimental results on $ ext{eta}^ ext{' }$ decays, including observations, CP violation searches, and rare decay limits, utilizing the large BESIII data sample.

Findings

Observation of $ ext{eta}^ ext{' } ightarrow ext{pi}^+ ext{pi}^- ext{mu}^+ ext{mu}^-$ decay

Search for CP violation in $ ext{eta}^ ext{' } ightarrow ext{pi}^+ ext{pi}^- ext{e}^+ ext{e}^-$ decay

Limits set on rare decays $ ext{eta}^ ext{' } ightarrow 4 ext{pi}^0$ and $ ext{eta}^ ext{' } ightarrow ext{gamma} ext{gamma} ext{eta}$

Abstract

The world's largest sample of $J/\psi$ events accumulated at the BESIII dector offers a unique opportunity to investigate $\eta$ and $\eta^\prime$ physics via two body $J/\psi$ radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in $\eta/\eta^\prime$ decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this report, including the observation of $\eta^\prime\rightarrow\pi^+\pi^-\mu^+\mu^-$, the study of $\eta^\prime\rightarrow\pi^+\pi^-e^+e^-$, and search for $CP$-violation in this decay, search for the rare decays of $\eta^\prime\rightarrow4\pi^0$ and $\eta^\prime\rightarrow\gamma\gamma\eta$, as well as the precision measurement of the branching fraction of $\eta^\prime$ decays.