The VII-th International Conference on the Initial Stages of High-Energy Nuclear Collisions : Initial Stages 2023

Interplay of longitudinal and transverse expansion in the kinetic dynamics of heavy-ion collisions

Not scheduled

20m

Copenhagen

Poster The initial stages and nuclear structure in heavy-ion collisions

Speaker

Piotr Bozek (AGH University of Science and Technology)

Description

The early dynamics in heavy-ion collisions involves a rapid, far from equilibrium evolution. This early pre-equilibrium stage of the dynamics can be modeled using kinetic equations. The effect of this pre-equilibrium stage on final observables derived from transverse momenta of emitted particles is small. The kinetic equations in the relaxation time approximation for a non-boost invariant system are solved (P.Bozek arXiv:2212.06018). The asymmetry of the flow with respect to the reaction plane at different rapidities is found to be very sensitive to the degree of non-equilibrium in the evolution. This suggests that the rapidity odd directed flow could be studiedto identify the occurrence of non-equilibrium effects and to estimate the asymmetry of the pressure between the longitudinal and transverse directions in the collision. The study of kinetic evolution in the longitudinal allows also a modelling of the early pre-Bjorken flow stage of the equilibration.