Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Limiting attractors in heavy-ion collisions

Boguslavski, K. ; Kurkela, A. ; Lappi, T. ; Lindenbauer, F. and Peuron, J. LU orcid (2024) In Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 852.
Abstract

We study universal features of the hydrodynamization process in heavy-ion collisions using QCD kinetic theory simulations for a wide range of couplings. We introduce the new concept of limiting attractors, which are obtained by extrapolation to vanishing and strong couplings. While the hydrodynamic limiting attractor emerges at strong couplings and is governed by the viscosity-related relaxation time scale τR, we identify a bottom-up limiting attractor at weak couplings. It corresponds to the late stages of the perturbative bottom-up thermalization scenario and exhibits isotropization on the time scale τBMSS=αs−13/5/Qs. In contrast to hydrodynamic limiting attractors, at finite... (More)

We study universal features of the hydrodynamization process in heavy-ion collisions using QCD kinetic theory simulations for a wide range of couplings. We introduce the new concept of limiting attractors, which are obtained by extrapolation to vanishing and strong couplings. While the hydrodynamic limiting attractor emerges at strong couplings and is governed by the viscosity-related relaxation time scale τR, we identify a bottom-up limiting attractor at weak couplings. It corresponds to the late stages of the perturbative bottom-up thermalization scenario and exhibits isotropization on the time scale τBMSS=αs−13/5/Qs. In contrast to hydrodynamic limiting attractors, at finite couplings the bottom-up limiting attractor provides a good universal description of the pre-hydrodynamic evolution of jet and heavy-quark momentum broadening ratios qˆyy/qˆzz and κT/κz. We also provide parametrizations for these ratios for phenomenological studies of pre-equilibrium effects on jets and heavy quarks.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
volume
852
article number
138623
publisher
Elsevier
external identifiers
  • scopus:85189892668
ISSN
0370-2693
DOI
10.1016/j.physletb.2024.138623
language
English
LU publication?
yes
id
ba29a62b-737b-4ad5-ac72-e8eaf66baa3d
date added to LUP
2024-04-24 14:16:37
date last changed
2024-04-24 14:17:35
@article{ba29a62b-737b-4ad5-ac72-e8eaf66baa3d,
  abstract     = {{<p>We study universal features of the hydrodynamization process in heavy-ion collisions using QCD kinetic theory simulations for a wide range of couplings. We introduce the new concept of limiting attractors, which are obtained by extrapolation to vanishing and strong couplings. While the hydrodynamic limiting attractor emerges at strong couplings and is governed by the viscosity-related relaxation time scale τ<sub>R</sub>, we identify a bottom-up limiting attractor at weak couplings. It corresponds to the late stages of the perturbative bottom-up thermalization scenario and exhibits isotropization on the time scale τ<sub>BMSS</sub>=α<sub>s</sub><sup>−13/5</sup>/Q<sub>s</sub>. In contrast to hydrodynamic limiting attractors, at finite couplings the bottom-up limiting attractor provides a good universal description of the pre-hydrodynamic evolution of jet and heavy-quark momentum broadening ratios qˆ<sup>yy</sup>/qˆ<sup>zz</sup> and κ<sub>T</sub>/κ<sub>z</sub>. We also provide parametrizations for these ratios for phenomenological studies of pre-equilibrium effects on jets and heavy quarks.</p>}},
  author       = {{Boguslavski, K. and Kurkela, A. and Lappi, T. and Lindenbauer, F. and Peuron, J.}},
  issn         = {{0370-2693}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics}},
  title        = {{Limiting attractors in heavy-ion collisions}},
  url          = {{http://dx.doi.org/10.1016/j.physletb.2024.138623}},
  doi          = {{10.1016/j.physletb.2024.138623}},
  volume       = {{852}},
  year         = {{2024}},
}