TY - JOUR AU - Xiao, C. W. AU - Dias, J. M. AU - Dai, L. R. AU - Liang, W. H. AU - Oset, E. PY - 2024 DA - 2024// TI - Triangle singularity in the J/ψ → ϕ π+ a−0(π−η) ,ϕ π− a+0(π+η) decays T2 - Phys. Rev. D JO - Physical Review D SP - 074033 EP - 11pp VL - 109 IS - 7 PB - Amer Physical Soc AB - We study the J= psi -> phi pi + a 0 ( 980 ) – ( a – 0 -> pi – eta ) decay, evaluating the double mass distribution in terms of the pi – eta and pi + a – 0 invariant masses. We show that the pi – eta mass distribution exhibits the typical cusp structure of the a 0 ( 980 ) seen in recent high statistics experiments, and the pi + a – 0 spectrum shows clearly a peak around M inv ( pi + a – 0 ) = 1420 MeV, corresponding to a triangle singularity. When integrating over the two invariant masses we find a branching ratio for this decay of the order of 10 – 5 , which is easily accessible in present laboratories. We also call attention to the fact that the signal obtained is compatible with a bump experimentally observed in the eta pi + pi – mass distribution in the J= psi -> phi eta pi + pi – decay and encourage further analysis to extract from there the phi pi + a – 0 and phi pi – a + 0 decay modes. SN - 2470-0010 UR - https://arxiv.org/abs/2402.17584 UR - https://doi.org/10.1103/PhysRevD.109.074033 DO - 10.1103/PhysRevD.109.074033 LA - English N1 - WOS:001236271000012 ID - Xiao_etal2024 ER -