Theoretical study on η′ → π+π−π+(0)π−(0)

Abstract

The η′ meson is associated with the U(1) anomaly. In this paper, a successful effective chiral theory of mesons has been applied to study the anomalous decays of η′→π+π−π+(0)π−(0). Contribution of triangle and box diagrams is calculated, which indicates that the box anomaly has a significant contribution to the decay amplitudes. We predict branching ratios of Br(η′→π+π−π+π−)=12Br(η′→π+π−π0π0)=(8.3±1.2)×10−5, which is in good agreement with BESIII measurement.