We study the J/ψ→K+K−f0(980)(a0(980)) reaction and find that the mechanism to produce this decay develops a triangle singularity around Minv(K−f0/K−a0)≈1515 MeV. The differential width dΓ/dMinv(K−f0/K−a0) shows a rapid growth around the invariant mass being 1515 MeV as a consequence of the triangle singularity of this mechanism, which is directly tied to the nature of the f0(980) and a0(980) as dynamically generated resonances from the interaction of pseudoscalar mesons. The branching ratios obtained for the J/ψ→K+K−f0(980)(a0(980)) decays are of the order of 10−5, accessible in present facilities, and we argue that their observation should provide relevant information concerning the nature of the low-lying scalar mesons.

This work is partly supported by the National Natural Science Foundation of China under Grants Nos. 11505158, 11565007, 11722540, and 11847317, the Fundamental Research Funds for the Central Universities, and the Academic Improvement Project of Zhengzhou University. This work is also partly supported by the Spanish Ministerio de Economia y Competitividad and European FEDER funds under the contract number FIS2011-28853-C02-01, FIS2011-28853-C02-02, FIS2014-57026-REDT, FIS2014-51948-C2-1-P, and FIS2014-51948-C2-2-P.

Peer reviewed