Light meson decays at BESIII

Abstract

At present the world's largest sample of 1.3 billion J/psi decay has been collected by the BESIII detector, which provides a unique opportunity to investigate light meson decays. The η and η′ hadronic decays are sensitive tools for the investigations of π-π and η-π interactions, symmetry breaking, and for testing the Chiral Perturbation Theory. In this article, BESIII presents new results on amplitude analyses of the Dalitz decays η′ → 3π, η′ → ηππ, η′ → γππ and η′ → γγπ 0 , on the observation of new decay modes and on searches for rare or forbidden decays. The a 0 (980)f 0 (980) mixing is an important probe to the nature of these two light scalars. The first observation of a 0 (980)f 0 (980) mixing will be presented.