%0 Journal Article
%T Triangle singularity in the J/ψ → ϕ π+ a−0(π−η) ,ϕ π− a+0(π+η) decays
%A Xiao, C. W.
%A Dias, J. M.
%A Dai, L. R.
%A Liang, W. H.
%A Oset, E.
%J Physical Review D
%D 2024
%V 109
%N 7
%I Amer Physical Soc
%@ 2470-0010
%G English
%F Xiao_etal2024
%O WOS:001236271000012
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=6212), last updated on Mon, 29 Jul 2024 06:47:10 +0000
%X 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.
%R 10.1103/PhysRevD.109.074033
%U https://arxiv.org/abs/2402.17584
%U https://doi.org/10.1103/PhysRevD.109.074033
%P 074033-11pp