Heavy quarkonium photoproduction in ultrarelativistic heavy ion collisions

摘要

Based on the factorization formalism of nonrelativistic quantumchromodynamics (NRQCD), we calculate the production cross section for thecharmonium and the bottomonium produced by the hard photoproduction processesand fragmentation processes in relativistic heavy ion collisions. It is shownthat the existing experimental data on heavy quarkonium production at the LargeHadron Collider (LHC) can be described in the framework of the NRQCD formalism,and the phenomenological values of matrix elements for color-singlet andcolor-octet components give the main contribution. The numerical results ofphotoproduction processes and fragmentation processes for the heavy quarkoniumproduction become prominent in p-p collisions and Pb-Pb collisions at LHCenergies.