Attractors for Flow Observables in 2+1D Bjorken Flow

Abstract

We examine the capabilities of second-order Israel-Stewart-type hydrodynamics to capture the early-time behaviour of the quark-gluon plasma created in heavy-ion collisions. We point out that at very early times, the dynamics of the fireball is governed by the local 0+1-D Bjorken flow attractor due to the rapid expansion along the longitudinal direction. Discrepancies between hydrodynamics and kinetic theory in this far-from-equilibrium regime leads to disagreement at the level of late-time observables, such as elliptic flow. We show that rescaling the initial energy-density profile for hydrodynamics accounts for such discrepancies, restoring agreement with kinetic theory for large opacities (small shear viscosity / large system size / high energy).

6 pages, 3 figures. Contribution to the TIM-2022 conference proceedings

References in corpus (4)

• Establishing the Range of Applicability of Hydrodynamics in High-Energy Collisions
• Opacity dependence of transverse flow, pre-equilibrium and applicability of hydrodynamics in heavy-ion collisions
• Statistical analysis of initial state and final state response in heavy-ion collisions
• Fast kinetic simulator for relativistic matter

Cited by in corpus (1)

• Extended applicability domain of viscous anisotropic hydrodynamics in (2+1)-D Bjorken flow with transverse expansion