Title: Higher order and anisotropic hydrodynamics for Bjorken and Gubser flows

Abstract

We study the evolution of hydrodynamic and nonhydrodynamic moments of the distribution function using anisotropic and third-order Chapman-Enskog hydrodynamics for systems undergoing Bjorken and Gubser flows. The hydrodynamic results are compared with the exact solution of the Boltzmann equation with a collision term in relaxation time approximation. While the evolution of the hydrodynamic moments of the distribution function (i.e., of the energy momentum tensor) can be described with high accuracy by both hydrodynamic approximation schemes, their description of the evolution of the entropy of the system is much less precise. We attribute this to large contributions from nonhydrodynamic modes coupling into the entropy evolution, which are not well captured by the hydrodynamic approximations. The differences between the exact solution and the hydrodynamic approximations are larger for the third-order Chapman-Enskog hydrodynamics than for anisotropic hydrodynamics, which effectively resums some of the dissipative effects from anisotropic expansion to all orders in the anisotropy, and are larger for Gubser flow than for Bjorken flow. Overall, anisotropic hydrodynamics provides the most precise macroscopic description for these highly anisotropically expanding systems.

Authors:

Chattopadhyay, Chandrodoy ^[1]; Heinz, Ulrich ^[2]; Pal, Subrata ^[1]; Vujanovic, Gojko ^[3]

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+ Show Author Affiliations

1. Tata Inst. of Fundamental Research, Mumbai (India). Dept. of Nuclear and Atomic Physics
2. The Ohio State Univ., Columbus, OH (United States). Dept. of Physics; European Organization for Nuclear Research (CERN), Geneva (Switzerland). Theoretical Physics Dept.
3. The Ohio State Univ., Columbus, OH (United States). Dept. of Physics

Publication Date:

2018-06-14

Research Org.:

The Ohio State Univ., Columbus, OH (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF)

OSTI Identifier:

1454315

Alternate Identifier(s):

OSTI ID: 1503828

Grant/Contract Number:  

SC0004286; ACI-1550223

Resource Type:

Published Article

Journal Name:

Physical Review C

Additional Journal Information:

Journal Volume: 97; Journal Issue: 6; Journal ID: ISSN 2469-9985

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

73 NUCLEAR PHYSICS AND RADIATION PHYSICS; hydrodynamic models; quark-gluon plasma; relativistic heavy-ion collisions