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Title: Diffusive dynamics of critical fluctuations near the QCD critical point

Abstract

A quantitatively reliable theoretical description of the dynamics of fluctuations in nonequilibrium is indispensable in the experimental search for the QCD critical point by means of ultrarelativistic heavy-ion collisions. Herein we consider the fluctuations of the net-baryon density which becomes the slow, critical mode near the critical point. Due to net-baryon number conservation the dynamics is described by the fluid dynamical diffusion equation, which we extend to contain a white noise stochastic current. Including nonlinear couplings from the 3d Ising model universality class in the free energy functional, we solve the fully interacting theory in a finite size system. We observe that purely Gaussian white noise generates non-Gaussian fluctuations, but finite size effects and exact net-baryon number conservation lead to significant deviations from the expected behavior in equilibrated systems. In particular the skewness shows a qualitative deviation from infinite volume expectations.With this benchmark established we study the real-time dynamics of the fluctuations. We recover the expected dynamical scaling behavior and observe retardation effects and the impact of critical slowing down near the pseudocritical temperature.

Authors:
 [1];  [2];  [3];  [4]
  1. Univ. de Nantes (France); GSI-Darmstadt (Germany). ExtreMe Matter Inst. (EMMI)
  2. Univ. of Wroclaw (Poland)
  3. North Carolina State Univ., Raleigh, NC (United States)
  4. Duke Univ., Durham, NC (United States)
Publication Date:
Research Org.:
North Carolina State Univ., Raleigh, NC (United States); Duke Univ., Durham, NC (United States)
Sponsoring Org.:
USDOE Office of Science (SC); European Union's Horizon 2020; National Science Centre of Poland (NCN); DoE Beam Energy Scan Theory (BEST) Topical Collaboration; ExtreMe Matter Institute (EMMI)
OSTI Identifier:
1609460
Alternate Identifier(s):
OSTI ID: 1546258
Grant/Contract Number:  
FG02-03ER41260; FG02-05ER41367; 665778; UMO-2016/21/P/ST2/ 04035
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 99; Journal Issue: 11; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Astronomy & Astrophysics; Physics

Citation Formats

Nahrgang, Marlene, Bluhm, Marcus, Schäfer, Thomas, and Bass, Steffen A. Diffusive dynamics of critical fluctuations near the QCD critical point. United States: N. p., 2019. Web. https://doi.org/10.1103/physrevd.99.116015.
Nahrgang, Marlene, Bluhm, Marcus, Schäfer, Thomas, & Bass, Steffen A. Diffusive dynamics of critical fluctuations near the QCD critical point. United States. https://doi.org/10.1103/physrevd.99.116015
Nahrgang, Marlene, Bluhm, Marcus, Schäfer, Thomas, and Bass, Steffen A. Thu . "Diffusive dynamics of critical fluctuations near the QCD critical point". United States. https://doi.org/10.1103/physrevd.99.116015. https://www.osti.gov/servlets/purl/1609460.
@article{osti_1609460,
title = {Diffusive dynamics of critical fluctuations near the QCD critical point},
author = {Nahrgang, Marlene and Bluhm, Marcus and Schäfer, Thomas and Bass, Steffen A.},
abstractNote = {A quantitatively reliable theoretical description of the dynamics of fluctuations in nonequilibrium is indispensable in the experimental search for the QCD critical point by means of ultrarelativistic heavy-ion collisions. Herein we consider the fluctuations of the net-baryon density which becomes the slow, critical mode near the critical point. Due to net-baryon number conservation the dynamics is described by the fluid dynamical diffusion equation, which we extend to contain a white noise stochastic current. Including nonlinear couplings from the 3d Ising model universality class in the free energy functional, we solve the fully interacting theory in a finite size system. We observe that purely Gaussian white noise generates non-Gaussian fluctuations, but finite size effects and exact net-baryon number conservation lead to significant deviations from the expected behavior in equilibrated systems. In particular the skewness shows a qualitative deviation from infinite volume expectations.With this benchmark established we study the real-time dynamics of the fluctuations. We recover the expected dynamical scaling behavior and observe retardation effects and the impact of critical slowing down near the pseudocritical temperature.},
doi = {10.1103/physrevd.99.116015},
journal = {Physical Review D},
number = 11,
volume = 99,
place = {United States},
year = {2019},
month = {6}
}

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Cited by: 8 works
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Works referenced in this record:

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    Microcanonical Particlization with Local Conservation Laws
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