Approaching equilibrium in heavy-ion collisions

The aim of this paper is to obtain a consistent and precise understanding of the available data and the development of a model with few parameters and considerable predictive power. In the following section the nonequilibrium statistical treatment of the relative motion is outlined. The time scales which determine the validity of the approach are mentioned, and the moment equations are discussed. A classical model to evaluate the mean energy and angular-momentum loss as well as the interaction time is described in sect. 3. The nucleon exchange occurring during nuclear contact can also be treated as a transport process. In sect. 4 we discuss calculated element distributions and compare with experimental results. An observed retardation of the charge drift requires special attention. In sect. 5 we treat the shape relaxation as a dissipative process and present a model calculation. The angular-momentum transport is reconsidered in sect. 6, with emphasis on the statistical fluctuations of the dissipated angular momentum. Calculated multidifferential cross-sections are compared with experiment in sect. 7. Finally we discuss in sect. 8 how nuclear shell structure can possibly affect the nucleon diffusion process, and draw the conclusions in sect. 9. (orig./HSI)