An overview of $\eta$ and $\eta^{\prime}$ decays at BESIII

TL;DR

BESIII's extensive dataset enables comprehensive studies of $ta$ and $ta^{}$ decays, revealing new decay modes, dynamics, and rare processes with high sensitivity, advancing understanding of light meson physics.

Contribution

This review summarizes the significant results on $ta$ and $ta^{}$ decays obtained at BESIII, highlighting new decay observations and analysis techniques.

Findings

Observation of new radiative and Dalitz decays

Detection of rare/forbidden decays with sensitivity up to 10^{-5}

Detailed insights into decay dynamics of $ta$ and $ta^{}$

Abstract

The world's largest sample of 1.31 billion $J/\psi$ events accumulated at the BESIII detector, provides a unique opportunity to investigate $\eta$ and $\eta^\prime$ physics via two body $J/\psi$ radiative or hadronic decays. For many $\eta^\prime$ decay channels the low background data samples are up to three orders of magnitude larger than collected in any previous experiment. Here we review the most significant results on $\eta$ and $\eta^\prime$ obtained at BESIII so far. The analyses range from detailed studies of the common decays dynamics, observations of new radiative and Dalitz decays, and search for rare/forbidden decays with sensitivity up to $\cal{B}\sim 10^{-5}$. Finally, prospects of the forthcoming runs at $J/\psi$ peak for the $\eta$ and $\eta^\prime$ physics are discussed.