2025/11/18 by Zhang, Jin-Peng, Wang, Guan-Yu, Zhang, Wen-Chao +7
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · doi:10.48550/arxiv.2511.14105
openalex publication_date 2025/11/18 · openalex created_date 2025/11/20 · openalex updated_date 2026/07/28
We investigate the inclusive J/ψ production in proton-proton (pp) collisions at center-of-mass energies √(s) = 5.02, 7, and 13 TeV using the PACIAE 4.0 model. This model extends PYTHIA 8.3 by incorporating partonic and hadronic rescatterings before and after hadronization, respectively. Compared to our earlier study [K.-F. Ye et al., Phys. Rev. C 109, 035201 (2024)], which considered only the color-singlet processes, the present work includes both the color-singlet and color-octet contributions within the non-relativistic QCD (NRQCD) framework. In addition to NRQCD, we also consider the contributions from the cluster collapse and weak decays of b-hadrons. We find that the simulated inclusive J/ψ transverse momentum differential cross sections agree well with the experimental data at both the middle and forward rapidities. We provide a quantitative analysis of the relative contributions for different production mechanisms and their energy and rapidity dependence in the inclusive J/ψ production. Furthermore, we offer a quantification of the relative contributions of the various components and their energy and rapidity dependence in the NRQCD channels, including the direct production via the hard scattering and the feed-down from the decays of heavier charmonium states such as ψ(2S), χc0, χc1, and χc2. Finally, we examine the effects of partonic and hadronic rescatterings and offer the quantitative estimate of their impact on the J/ψ production. These results are entirely new and represent a significant step forward in understanding the mechanisms of the inclusive J/ψ production in high-energy pp collisions.