Viscosity and the equation of state in high energy heavy-ion reactions

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.47.2782· OSTI ID:6497565

Schmidt, W; Katscher, U; Waldhauser, B; Maruhn, J A; Stoecker, H; Greiner, W ^[1]

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1. Institut fuer Theoretische Physik, J. W. Goethe-Universitaet, Robert-Mayer-Str. 8-10, D-6000 Frankfurt-am-Main (Germany)

Viscous hydrodynamic calculations of high energy heavy-ion collisions (Nb-Nb and Au-Au) from 200 to 800 MeV/nucleon are presented. The resulting baryon rapidity distributions, the in-plane transverse momentum transfer (bounce-off), and the azimuthal dependence of the midrapidity particles (off-plane squeeze out) compare well with Plastic Ball data. We find that the considered observables are sensitive both to the nuclear equation of state and to the nuclear shear viscosity [eta]. Transverse momentum distributions indicate a high shear viscosity ([eta][approx]60 MeV/fm[sup 2] [ital c]) in the compression zone, in agreement with nuclear matter estimates. The bulk viscosity [zeta] influences only the entropy production during the expansion stage; collective observables like flow and [ital dN]/[ital dY] do not depend strongly on [zeta]. The recently observed off-plane ([phi]=90[degree]) squeeze-out, which is found in the [ital triple]-[ital differential] rapidity distribution, exhibits the strongest sensitivity to the nuclear equation of state. It is demonstrated that for very central collisions, [ital b]=1 fm, the squeeze-out is visible even in the double-differential cross section. This is experimentally accessible by studying azimuthally symmetric events, as confirmed recently by data of the European 4[pi] detector collaboration at Gesellchaft fuer Schwerionforschung Darmstadt.

• OSTI ID: 6497565
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 47:6; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
GOLD 199 TARGET
GOLD 197 REACTIONS
HEAVY ION REACTIONS
HYDRODYNAMIC MODEL
NIOBIUM 93 TARGET
NIOBIUM 93 REACTIONS
ANGULAR DISTRIBUTION
BARYONS
DIFFERENTIAL CROSS SECTIONS
EQUATIONS OF STATE
NUCLEAR MATTER
RELATIVISTIC RANGE
TRANSVERSE MOMENTUM
VISCOUS FLOW
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
FERMIONS
FLUID FLOW
HADRONS
LINEAR MOMENTUM
MATHEMATICAL MODELS
MATTER
NUCLEAR REACTIONS
PARTICLE MODELS
STATISTICAL MODELS
TARGETS
THERMODYNAMIC MODEL
663300* - Nuclear Reactions & Scattering
General- (1992-)
663450 - Heavy-Ion-Induced Reactions & Scattering- (1992-)
663560 - Nuclear Mass Ranges- A=90-149- (1992-)
663580 - Nuclear Mass Ranges- A=190-219- (1992-)