Charmonium Production from the Secondary Collisions at LHC Energy

Abstract

We consider the charmonium production in thermalized hadronic medium created in ultrarelativistic heavy ion collisions at LHC energy. The calculations for the secondary $J/ψ$ and $ψ^,$ production by $D\bar D$ annihilation are performed within a kinetic model taking into account the space-time evolution of a longitudinally and transversely expanding medium. We show that the secondary charmonium production appears almost entirely during the mixed phase and it is very sensitive to the charmonium dissociation cross section with co-moving hadrons. Within the most likely scenario for the dissociation cross section of the $J/ψ$ mesons their regeneration in the hadronic medium will be negligible. The secondary production of $ψ^,$ mesons however, due to their large cross section above the threshold, can substantially exceed the primary yield.