Evolution of the concept of Quark Matter: the Ianus face of the heavy ion collisions

Abstract

Since the beginning of the efforts to produce and understand quark matter large changes developed in the ideas of description of this matter. In the present paper we summarize some aspects of this development.

Comments: Talk given at 18th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2005 (QM 2005), Budapest, Hungary, 4-9 Aug 2005. 10 pages, 7 figures