2025/06/10 by Thanat Sangkhakrit, Sangkhakrit, Thanat, Attaphon Kaewsnod +11
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear physics research studies #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2506.08406
openalex publication_date 2025/06/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The χc1(3872) state, first observed by the Belle collaboration with its quantum numbers identified as JPC = 1++, has been the subject of extensive research due to its intriguing properties. Several theoretical interpretations have been proposed to explain its unique characteristics, including the χc1(2P) assignment, a molecular D*D/DD* configuration, a coupled-channel framework incorporating cc and di-meson degrees of freedom, and the compact tetraquark hypothesis. However, challenges remain in reconciling its mass coincidence with the threshold and the observed isospin violation within both the pure cc and compact tetraquark models. In this study, we examine the radiative decays of the χc1(1P) and χc1(3872) states in an effective field theory framework, incorporating triangle loops of D and D* mesons. The model parameters are calibrated based on the observed branching fraction of the radiative decay mode χc1(1P) → J/ψγ. Utilizing these fixed parameters, we predict the branching fractions R_χc1(3872) → J/ψγ ∼ 10-1 and R_χc1(3872) → ψ(2S) γ ∼ 10-2, and the relative fraction RΨγ ≈ 0.109. The work supports the argument that the χc1(3872) is unlikely a cc state.