2004/06/25 by D. V. Bugg, D.V. Bugg · 8 citations
Physics and Astronomy · #Annihilation #Atomic physics #Cusp (singularity) #Excitation #Geometry #High-Energy Particle Collisions Research #Nuclear physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scattering #hep-ph
paper · pdf · doi:10.1016/j.physletb.2004.07.047
published as Phys.Lett.B598:8-14,2004 · 15 pages, 5 figures. Submitted to Physics Letters B
arxiv created 2004/06/25 · openalex publication_date 2004/08/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The threshold p¯p peak in BES data for J/Ψ→γp¯p may be fitted as a cusp. It arises from the well-known threshold peak in p¯p elastic scattering due to annihilation. Several similar examples are discussed. The PS185 data for p¯p→Λ¯Λ require an almost identical cusp at the Λ¯Λ threshold. There is likewise a cusp at the ΣN threshold in K−d→π−(Λp). Similar cusps are likely to arise at thresholds for all 2-body de-excitation processes, providing the interaction is attractive; likely examples are Λp¯, Σp¯, and K¯Λ. The narrow peak observed by Belle at 3872 MeV in π+π−J/Ψ may be a JPC=1++ cusp due to the DD¯* threshold. The narrow Ξ*(1862) observed by NA49 may be due to a threshold cusp in Σ(1385)K¯ coupled to Ξπ and ΣK¯. The relation of cusps to known resonances such as f0(980) is discussed.