Fate of the initial state perturbations in heavy ion collisions. II. Glauber fluctuations and sounds

Journal Article · Thu Sep 15 00:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.84.034908· OSTI ID:21596777

Staig, Pilar; Shuryak, Edward ^[1]

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1. Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794 (United States)

Heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) are well described by the (nearly ideal) hydrodynamics for average events. In the present paper we study initial state fluctuations appearing on an event-by-event basis and the propagation of perturbations induced by them. We found that (i) fluctuations of several of the lowest harmonics have comparable magnitudes and (ii) that at least all odd harmonics are correlated in phase, (iii) thus indicating the local nature of fluctuations. We argue that such local perturbations should be the source of the ''tiny bang,'' a pulse of sound propagating from it. We identify its two fundamental scales as (i) the ''sound horizon'' (analogous to the absolute ruler in cosmic microwave background and galaxy distributions) and (ii) the ''viscous horizon'' separating damped and undamped harmonics. We then qualitatively describe how one can determine them from the data and thus determine two fundamental parameters of the matter: the (average) speed of sound and viscosity. The rest of the paper explains how one can study mutual coherence of various harmonics. For that, one should go beyond the two-particle correlations to three (or more) particles. Mutual coherence is important for the picture of propagating sound waves.

• OSTI ID: 21596777
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 84, Issue 3; Other Information: DOI: 10.1103/PhysRevC.84.034908; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BNL
BROOKHAVEN RHIC
CORRELATIONS
DISTRIBUTION
DISTURBANCES
FLUCTUATIONS
GLAUBER THEORY
HARMONICS
HEAVY ION REACTIONS
PERTURBATION THEORY
PULSES
RELICT RADIATION
SOUND WAVES
ACCELERATORS
ELECTROMAGNETIC RADIATION
HEAVY ION ACCELERATORS
MICROWAVE RADIATION
NATIONAL ORGANIZATIONS
NUCLEAR REACTIONS
OSCILLATIONS
RADIATIONS
STORAGE RINGS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
VARIATIONS