Further insights into the "ρπ puzzle"

Original · EN

Based on a systematic investigation of J/ψ(ψ′)→ VP, where V and P stand for light vector and pseudoscalar mesons, we identify the role played by the electromagnetic (EM) transitions and intermediate meson loop transitions, which are essential ingredients for understanding the J/ψ and ψ′ couplings to VP. We show that on the one hand, the EM transitions have relatively larger interferences in ψ′→ ρπ and K*K+c.c. as explicitly shown by vector meson dominance (VMD). On the other hand, the strong decay of ψ′ receives relatively larger destructive interferences from the intermediate meson loop transitions. By identifying these mechanisms in an overall study of J/ψ(ψ′)→ VP, we provide a coherent understanding of the so-called "ρπ puzzle".