Light meson decays at BESIII

Beihang University, Beijing, 100083, People’s Republic of China

^* e-mail: yanwc@buaa.edu.cn

Published online: 1 February 2019

Abstract

The BESIII experiment has accumulated the world’s largest data samples of 1.3 billion J/ψ events and 0.45 billion ψ(3686) events, which provide a unique opportunity to investigate light meson decays. The η and η′ decays are sensitive tools for investigations of π − π and η − π interactions, symmetry breaking, and serve as a test of chiral perturbation theory. In recent years considerable results on η and η′ decays were achieved at the BESIII experiment. In this proceeding, we present the significant progresses on amplitude analyses of Dalitz decays η' → 3π,η' → ηππ, and radiative decay η' → γπ⁺π⁻, η' → γγπ⁰. Additionally, the $a_0^0\left(980\right)-f_0\left(980\right)$ mixing is an important probe to the nature of those two lightest scalar mesons. The first observation of $a_0^0\left(980\right)-f_0\left(980\right)$ mixing is also presented, which will help to improve the understanding of the nature of $a_0^0\left(980\right)$ and f₀(980).