Nuclear Theory

University Of Arizona, Tucson AZ

Investigators

Abstract

0070828 Kohler This proposal concerns the properties of dense matter and in particular that of nuclear matter and nuclei. It is a theoretical study for example related to experiments involving collisions between heavy ions performed at laboratories around the world. The main object of my research is to obtain an understanding of these many-particle systems in a state of non-equilibrium as well as equilibrium and especially the processes leading to equilibration. The interactions and collisions between the constituent particles are of utmost important in this study and are also a subject of my study. The study involves modern quantum-mechanical methods using a Green's function formulation of the problem. So-called transport equations were developped based on these techniques in the 60's but it is not until in the last few years that they have been the subject of numerical study. The availability of high-speed and large memory computers have made it possible to obtain exact solutions of these equations for some particular cases. I have developped efficient computer-programs and have been in the forefront of these applications with publications related not only to nuclear problems but also to semiconductor and plasma physics problems. The study of non-equilibrium phenomena is not new in physics. They have in fact been the subject of intense study within the realm of Statistical Mechanics for over one-hundred years especially since the work of Boltzmann who gave us the H-theorem and the famous Boltzmann transport equation. An enormous amount of discussions regarding extensions and also critique of this equation has ensued. It has played an undisputed role in the development of both equilibrium and non-equlibrium statistical mechanics and for quantative microscopic calculations of matter properties like conduction of heat and viscosity. It has been used in analyzing experiments with collisions between heavy ions. Even so it is however a classical equation with limited applicability to quantum systems like nuclei. The quantum-mechanical methods used in my study supersedes the Boltzman equation which on the other hand can be derived as a classical limit. Memory and correlation effects are included. Collective, pionic and relativistic effects are also within reach by these new methods. The quark-gluon plasma is another system that lies within reach.