Charmonium production from 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 DD 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.

Hadronic form factors and theJ/ψsecondary production cross section: An update

“…We believe that our results are useful for numerical simulations of heavy ion collisions, such as those performed in Refs. [2][3][4][5] and [22][23][24]. The calculation of the cross sections of the processes considered here are complete.…”

Quantum mechanical model for J/ψ suppression in the LHC era

“…The case of absorption appears when the imaginary part is Im[ω 2 (T )] < 0. The regeneration scenario [31,32,34,35,36,37,38] corresponds to Im[ω 2 (T )] > 0 in the THO model which stems from the coupling of the charmonium hamiltonian to open charm channels. In addition we shall consider a gaussian wave function for initial QQ state.…”

“…Once the partial densities of open charm mesons becomes nonnegligible, also the reverse processes of charmonium regeneration in channels like, e.g., D +D → J/ψ + ρ will occur. J/ψ re-generation shall give important contributions to charmonium production in heavy-ion collisions already at RHIC [31,32,33,34,35,36] and the more at the LHC [37,38]. The situation is well summarized in two recent reviews [39,40].…”

Heavy quark measurements with ALICE

“…First of all the signals will be sitting on top of a complex combinatorial background, mainly coming from open charm and open bottom decay [7]. Then, in addition to prompt charmonia produced "directly" via hard scattering, secondary charmonia can be produced from bottom decay [8], DD annihilation [9,10] and statistical hadronization [11,12,13]. Furthermore, the SPS results have demonstrated that the study of onium suppression must be closely joined to the study of open heavy flavours because both open and hidden quarkonia arise from the same underlying production mechanism.…”