Revealing dipion correlations for the observed substructure near the π + π − mass threshold in ψ ( 3686 ) → J / ψ π + π −
Abstract
Based on the world’s largest ψ ( 3686 ) data sample, the BESIII Collaboration recently reported a substructure near the π + π − mass threshold in the decay ψ ( 3686 ) → J / ψ π + π − , challenging the established understanding of the dipion invariant mass spectrum. We propose that this substructure arises directly from dipion correlations. Using a chiral unitary approach, we successfully reproduce the observed anomaly, thereby providing strong evidence of dipion correlation in heavy quarkonium decays. This approach also allows us to predict the corresponding dipion correlation function.
Fields of Study & Subjects
Quantum Chromodynamics and Particle Interactions
Particle physics theoretical and experimental studies
Black Holes and Theoretical Physics
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Publisher
- American Physical Society (APS)
- Volume
- 113
- Issue
- 3
- Publication date
- 22 January 2026
- Language
- EN