Coherent collective flow versus independent two-nucleon collisions in central high-energy heavy-ion collisions

Journal Article · Sat May 01 04:00:00 EDT 1982 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.25.2491· OSTI ID:5093896

Nix, J R; Strottman, D; Yariv, Y; Fraenkel, Z

For central collisions in the reaction /sup 20/Ne+/sup 238/U at a laboratory bombarding energy per nucleon of 393 MeV, we calculate the cross section d/sup 2/sigma/dE d..cap omega.. for outgoing charged particles by means of a relativistic intranuclear cascade, conventional relativistic nuclear fluid dynamics, and relativistic nuclear two-fluid dynamics. The results of the three calculations are compared with recent high-multiplicity-selected central-collision experimental data of Stock et al., including contributions from protons, deuterons, and tritons. The intranuclear cascade reproduces most features of the experimental data except the observed sidewards peaking in the angular distributions at low outgoing energy, predicting instead angular distributions that are forward peaked at all outgoing energies, to within statistical errors. Conventional nuclear fluid dynamics fails to reproduce the experimental data in two important respects: (1) the predicted energy spectra in forward directions decrease too rapidly with increasing outgoing energy and (2) the predicted angular distributions are too narrow and peak at increasingly larger angles with increasing outgoing energy, opposite to the experimental trend. Nuclear two-fluid dynamics predicts sidewards peaking for central collisions at intermediate outgoing energy that is in approximate agreement with experimental results, although the calculated peak is somewhat sharper than the experimental peak. With qualifications arising from the possible importance of contributions from large impact parameters, heavy composite particles, Coulomb effects, and thermal folding, we conclude that in central high-energy heavy-ion collisions the target and projectile interpenetrate substantially but that some degree of coherent collective flow is involved.

• Research Organization: Max-Planck-Institut fuer Kernphysik, D-6900 Heidelberg, Federal Republic of Germany
• OSTI ID: 5093896
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 25:5; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

652015* -- Nuclear Properties & Reactions
A=220 & above
Theoretical-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CHARGED-PARTICLE REACTIONS
COMPOUND-NUCLEUS REACTIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ENERGY RANGE
EQUATIONS
EQUATIONS OF STATE
GEV RANGE
GEV RANGE 01-10
HADRON-HADRON INTERACTIONS
HEAVY ION REACTIONS
INTERACTIONS
NEON 20 REACTIONS
NUCLEAR CASCADES
NUCLEAR REACTIONS
PARTICLE INTERACTIONS
TARGETS
URANIUM 238 TARGET