Hydrodynamic description of particle production in relativistic heavy-ion collisions

TL;DR

This paper presents a 2+1 hydrodynamic model for relativistic heavy-ion collisions that successfully describes RHIC data, predicts LHC outcomes, and addresses the early thermalization and HBT puzzles.

Contribution

It introduces a realistic equation of state, incorporates free-streaming and sudden equilibration stages, and combines hydrodynamics with statistical hadronization for improved modeling.

Findings

Achieved satisfactory description of RHIC soft hadronic data

Predicted observables for LHC heavy-ion collisions

Proposed solution to the RHIC HBT puzzle

Abstract

Our recently developed 2+1 (boost-invariant) hydrodynamic model has been presented and used to i) describe the soft hadronic data collected in the central region of the relativistic heavy-ion collisions at RHIC and ii) to make predictions for the heavy-ion collisions at the LHC energies. We have addressed both the one- and two-particle observables: the transverse momentum spectra, the elliptic flow coefficient v2, and the pion HBT radii. The realistic equation of state for strongly interacting matter has been constructed that interpolates between the hadron gas model and the results of the QCD lattice simulations. The computational platform has been constructed, which combines the results of our hydrodynamic code with the statistical hadronization model THERMINATOR. The satisfactory description of the soft hadronic RHIC data has been achieved with the standard initial conditions obtained from the optical limit of the Glauber model. Predictions for the future heavy-ion collisions at LHC have been formulated. The solution of the RHIC HBT puzzle has been proposed. It suggests the use of the modified Gaussian-type initial conditions for the energy density in the transverse plane. Finally, the processes of the free streaming of partons followed by the sudden equilibration have been incorporated in the model. The inclusion of the free-streaming stage allows for the delayed start of the hydrodynamic evolution, which is a desirable effect in the context of the early thermalization problem.