Light Meson Decays at BESIII

Shuangshi Fang,M Battaglieri,M Raggi,P Valente,F Curciarello,G Mandaglio

doi:10.1051/epjconf/201714201014

Abstract

At present the world’s largest sample of 1.3 billion J/ψ events was accumulated at the BESIII detector, which offers a unique place to study light meson decays. The recent results on the light meson decays are reviewed in this talk. An emphasis is put on the significant progresses on the study of η/η′ decays, including Dalitz plot analysis of η/η′ → πππ , observation of new decay modes (η′ → π + π − π +(0) π −(0) , η′ → ρ ± π ∓ , η′ → γe + e − and η′ → e + e − ω ), study of η′ → γπ + π − and search for the rare decay of η′ → Kπ . In addition, a prospect on the Dalitz plot analysis of ω → π + π − π 0 is presented.

Highlights

Light Meson Decays at BESIIIShuangshi Fang (for the BESIII Collaboration), a 1Institute of High Energy Physics, Beijing 100049, China
Abstract.At present the world’s largest sample of 1.3 billion J/ψ events was accumulated at the BESIII detector, which offers a unique place to study light meson decays
In particular for η, it is much heavier than the Goldstone bosons of broken chiral symmetry, and it has a special role in hadron physics because of its interpretation as a singlet state arising from the axial U(1) anomaly

Summary

Light Meson Decays at BESIII

Shuangshi Fang (for the BESIII Collaboration), a 1Institute of High Energy Physics, Beijing 100049, China. Η decay dynamics remains a subject of extensive theoretical studies aiming at extensions of chiral perturbation theory (ChPT). Guo, Kubis and Wirzba [7], using a combination of chiral perturbation theory (ChPT) and a vector-meson dominance (VMD) model, obtained the following prediction : B(η → π+π−π+π−) = (1.0 ± 0.3) × 10−4 and B(η → π+π−π0π0) = (2.4 ± 0.7) × 10−4. The branching fractions of η → π+π−π+(0)π−(0) are determined to be B(η → π+π−π+π−) = (8.53 ± 0.69 ± 0.64) × 10−5 and B(η → π+π−π0π0) = (1.82 ± 0.35 ± 0.18) × 10−4, which are consistent with the theoretical predictions based on a combination of chiral perturbation theory and vectormeson dominance [7], but not with the broken-SU6×O3 quark model [8]. Considerable theoretical efforts, see e.g. [10,11,12,13,14,15,16,17], have been invested to explain the discrepancy that the predicted

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Summary