Dynamical freeze-out condition in ultrarelativistic heavy ion collisions

Abstract

We determine the decoupling surfaces for the hydrodynamic description of heavy ion collisions at RHIC and LHC by comparing the local hydrodynamic expansion rate with the microscopic pion-pion scattering rate. The pion $p_T$ spectra for nuclear collisions at RHIC and LHC are computed by applying the Cooper-Frye procedure on the dynamical-decoupling surfaces, and compared with those obtained from the constant-temperature freeze-out surfaces. Comparison with RHIC data shows that the system indeed decouples when the expansion rate becomes comparable with the pion scattering rate. The dynamical decoupling based on the rates comparison also suggests that the effective decoupling temperature in central heavy ion collisions remains practically unchanged from RHIC to LHC.

7 pages, 9 figures

References in corpus (4)

• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Suppression of elliptic flow in a minimally viscous quark-gluon plasma
• Causal Viscous Hydrodynamics for Central Heavy-Ion Collisions
• Causal Viscous Hydrodynamics for Central Heavy-Ion Collisions II: Meson Spectra and HBT Radii

Cited by in corpus (2)

• Soft heavy-ion physics from hydrodynamics with statistical hadronization - predictions for the Large Hadron Collider
• Elliptic flow in nuclear collisions at the Large Hadron Collider