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  -