This award supports Professors Paul Ellis and Joseph Kapusta , plus a postdoctoral associate and two graduate students from the University of Minnesota, to collaborate in theoretical physics research with a group of scientists from the Universities of Bergen and Oslo in Norway and the University of Copenhagen in Denmark, under the coordination of Eivind Osnes of the University of Oslo. The Nordic scientists are part of a large Northern European Collaborative `Project on Relativistic Heavy Ion Collisions.` The general objective of that regional project is a better understanding of high-energy heavy-ion collisions, with particular emphasis on the properties of excited nuclear matter. It is providing theoretical support for experimental work by others dealing with energetic collisions of complex atomic nuclei. The specific involvement of the US researchers is studying the dynamical mechanisms of hadronization of the quark gluon plasma. Ultimately this will lead to a detailed description of hadronization, allowing conclusions to be drawn regarding the observable signals of hadronization. Broadly speaking, this research involves the theoretical study of nuclear collision at the highest energies available to experiment, which are expected within a few years to produce a Quark-Gluon Plasma. There is little basis yet for predicting reaction dynamics in the presence of a phase transition, and this research is attempting to provide theoretical insight into the evolution of the Quark-Gluon Plasma. It will also seek to define possible signals of hadronization and chiral symmetry breaking and restoration, and evaluate the sensitivity of the signals to underlying assumptions about the equation of state and correlation functions. Results of the proposed studies will increase knowledge of the structure of extended, stronglyinteracting matter at very small scale, which is relevant to understanding of the early universe, among other phenomena. The results will also be very useful in planning and evaluating future heavy ion experiments in large accelerators.
