Event-by-event shape and flow fluctuations of relativistic heavy-ion collision fireballs

Journal Article · Mon Aug 15 04:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.84.024911· OSTI ID:21596692

Zhi, Qiu; Heinz, Ulrich ^[1]

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1. Department of Physics, Ohio State University, Columbus, Ohio 43210-1117 (United States)

Heavy-ion collisions create deformed quark-gluon plasma (QGP) fireballs which explode anisotropically. The viscosity of the fireball matter determines its ability to convert the initial spatial deformation into momentum anisotropies that can be measured in the final hadron spectra. A quantitatively precise empirical extraction of the QGP viscosity thus requires a good understanding of the initial fireball deformation. This deformation fluctuates from event to event, and so does the finally observed momentum anisotropy. We present a harmonic decomposition of the initial fluctuations in shape and orientation of the fireball and perform event-by-event (2 + 1)-dimensional ideal fluid dynamical simulations to extract the resulting fluctuations in the magnitude and direction of the corresponding harmonic components of the final anisotropic flow at midrapidity. The final harmonic flow coefficients are found to depend nonlinearly on the initial harmonic eccentricity coefficients. We show that, on average, initial density fluctuations suppress the buildup of elliptic flow relative to what one obtains from a smooth initial profile of the same eccentricity and discuss implications for the phenomenological extraction of the QGP shear viscosity from experimental elliptic flow data.

• OSTI ID: 21596692
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 84; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANISOTROPY
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTARY PARTICLES
ENERGY RANGE
EXTRACTION
FLUCTUATIONS
FLUID FLOW
HADRONS
HEAVY ION REACTIONS
IDEAL FLOW
INCOMPRESSIBLE FLOW
MATTER
NUCLEAR REACTIONS
QUARK MATTER
RELATIVISTIC RANGE
SEPARATION PROCESSES
SIMULATION
SPECTRA
STEADY FLOW
THREE-DIMENSIONAL CALCULATIONS
VARIATIONS