http://cds.cern.ch/record/349359/files/9803035.pdf

Microscopic models for ultrarelativistic heavy ion collisions

New forms of QCD matter discovered at RHIC

“Quantum” molecular dynamics—a dynamical microscopic n-body approach to investigate fragment formation and the nuclear equation of state in heavy ion collisions

High energy heavy ion collisions—probing the equation of state of highly excited hardronic matter

The relativistic mean-field model of the nucleus is reviewed. It describes the nucleus as a system of Dirac nucleons which interact in a relativistic covariant manner via meson fields. The meson fields are treated as mean fields, i.e. as non-quantal c-number fields. The effect of the Dirac sea of the nucleons is neglected. The model is interpreted as a phenomenological ansatz providing a self-consistent relativistic description of nuclei and nuclear dynamics. It is viewed, so to say, as the relativistic generalisation of the Skyrme-Hartree-Fock ansatz. The capability and the limitations of the model to describe nuclear properties are discussed. Recent applications to spherical and deformed nuclei and to nuclear dynamics are presented.

https://iopscience.iop.org/article/10.1088/0034-4885/52/4/002/pdf

The relativistic mean-field description of nuclei and nuclear dynamics

Studying Walecka's mean-field theory we find that one can reproduce the observed binding energy and density of nuclear matter within experimental precision in an area characterized by a line in the coupling-constant plane. A part of this line defines systems which exhibit a phase transition around T/sub c/approx.200 MeV for zero baryon density. The rest corresponds to such systems where the phase transition is absent; in that case a peak appears in the specific heat around Tapprox.200 MeV. We interpret these results as indicating that the hadron phase of nuclear matter alone indicates the occurrence of an abrupt change in the bulk properties around rho/sub V/approx.0 and Tapprox.200 MeV.

/pdf/phase-transition-of-the-nucleon-antinucleon-plasma-in-a-4vfkwj98yq.pdf

Phase transition of the nucleon-antinucleon plasma in a relativistic mean-field theory

A kinetic-energy--flow analysis of multiplicity-selected collisions of /sup 93/Nb (E/sub lab/ = 400A MeV)+ /sup 93/Nb is performed on the basis of the nuclear fluid dynamical model. The effects of finite particle numbers on the flow tensor are explicitly taken into account. Strong sidewards peaks are predicted in dN/d costheta/sub F/, the distribution of event by event flow angles. This is in qualitative agreement with recent data from the ''Plastic Ball'' electronic detection system. Cascade simulations fail to reproduce the data.

Kinetic energy flow in Nb (400A MeV)+Nb: Evidence for hydrodynamic compression of nuclear matter

The fluid dynamical model is used to study the reactions $^{20}\mathrm{Ne}$+$^{238}\mathrm{U}$ and $^{40}\mathrm{Ar}$+$^{40}\mathrm{Ca}$ at ${E}_{\mathrm{lab}}=390$ MeV/nucleon. The calculated double differential cross sections ${d}^{2}\frac{\ensuremath{\sigma}}{d\ensuremath{\Omega}}\mathrm{dE}$ exhibit sidewards maxima in agreement with recent experimental data. The azimuthal dependence of the triple differential distributions, to be obtained from an event-by-event analysis of $4\ensuremath{\pi}$ exclusive experiments, can yield deeper insight into the collision process: Jets of nuclear matter are predicted with a strongly impact-parameter-dependent thrust angle ${\ensuremath{\theta}}_{\mathrm{jet}}(b)$.NUCLEAR REACTIONS Ar+Ca, Ne+U, ${E}_{\mathrm{lab}}=393$ MeV/nucleon, fluid dynamics with thermal breakup, double differential cross sections, azimuthal dependence of triple differential cross sections, event-by-event thrust analysis of $4\ensuremath{\pi}$ exclusive experiments.

/pdf/jets-of-nuclear-matter-from-high-energy-heavy-ion-collisions-1r9wqsi0sj.pdf

Jets of Nuclear Matter From High-energy Heavy Ion Collisions

Prospects of intermediate energy nuclear collisions

The predictions of a variety of current theoretical models of high-energy nuclear collisions are compared with recent experimental data for central collisions of /sup 20/Ne on /sup 238/U at E/sub lab/ = 393 MeV/n. The experimental observation of broad sideward maxima in the angular distributions of low- and medium-energy protons is reproduced by a nuclear fluid dynamical calculation with final freezeout of the protons. In contrast, the current intranuclear-cascade and simplified collision models predict forward-peaked angular distributions.

/pdf/nuclear-fluid-dynamics-versus-intranuclear-cascade-possible-4vzll5ba4i.pdf

G. Buchwald

Papers

Phase transition of the nucleon-antinucleon plasma in a relativistic mean-field theory

Kinetic energy flow in Nb (400A MeV)+Nb: Evidence for hydrodynamic compression of nuclear matter

Jets of Nuclear Matter From High-energy Heavy Ion Collisions

Prospects of intermediate energy nuclear collisions

Nuclear fluid dynamics versus intranuclear cascade--possible evidence for collective flow in central high energy nuclear collisions