2001/01/16 by A. S. Khrykin, Khrykin, A. S.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0101184
6 pages, LaTex, 2 eps-figures; Talk given at the XV International Seminar on High Energy Physics Problems, Dubna, Russia, September 25-29,2000, to be published in the proceeding
arxiv created 2001/01/16 · openalex publication_date 2001/01/16 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The energy spectrum for high energy γ-rays (Eγ≥ 10 MeV) from the process pp → γγX emitted at 900 in the laboratory frame has been measured at an energy below the pion production threshold, namely, at 216 MeV. The resulting photon energy spectrum extracted from γ- γ coincidence events consists of a narrow peak at a photon energy of about 24 MeV and a relatively broad peak in the energy range of (50 - 70) MeV. The statistical significance for both the narrow and broad peaks exceeds 5σ. This behavior of the photon energy spectrum is interpreted as a signature of the exotic dibaryon resonance d^⋆1 which is assumed to be formed in the radiative process pp → γd^⋆1 followed by its electromagnetic decay via the d^⋆1 → pp γ mode. The experimental spectrum is compared with those obtained by means of Monte Carlo simulations.