Study of experimental observables in relativistic heavy-ion collisions with relevance to the nuclear equation of state
The long-term goal of research in this subfield of physics is to identify the various possible phases of nuclear matter, and the nuclear equation of state in these phases. The data studied in this dissertation are most relevant to the hadron gas phase. The main work described is an analysis of sideward flow, an effect widely believed to be a good relative indicator of the maximum pressure generated in a nucleus-nucleus collision, and a useful probe of the nuclear equation of state when compared with an appropriate model. Nucleus-nucleus collisions are studied using data from a streamer chamber at Lawrence Berkeley Lab`s Bevalac accelerator. This detector offers 4{pi} solid angle coverage for emitted charged fragments. Azimuthal correlations are studied for fragment pairs and higher-order multiplets. It is demonstrated that no previous study of sideward flow has ruled out the possibility that the effect is dominated by a small number of correlated fragments in each event as opposed to being a collective motion to which most or all fragments contribute. A new degree of freedom, termed collectivity, is introduced. It is inferred that a high percentage of the forward-going fragments from collisions of Ar on Pb at 0.4A GeV and Ar on Ba at 1.2A GeV carry a component of the collective motion. The new flow observables have been compared in detail with the VUU nuclear transport model. This and other models do not consistently reproduce the experimental data for any assumed nuclear equation of state. The development of a fully realistic nuclear transport model is a difficult and long-term task, and it is concluded that the models tested have not yet reached a point where it is meaningful to infer quantitative information about the equation of state of the compressed hadron gas.
- Research Organization:
- Kent State Univ., OH (United States)
- OSTI ID:
- 102580
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1993
- Country of Publication:
- United States
- Language:
- English
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