A PERCOLATION TRANSITION IN ULTRARELATIVISTIC NUCLEAR COLLISIONS

Models based on Gribov-Regge theory and relativistic strings provide a sophisticated description of ultrarelativistic nuclear collisions. For reasonably heavy nuclei, strings cannot decay independent of each other: string-string interactions have to be taken into account. For this purpose, we introduce a percolation approach, which amounts to forming quark-matter droplets, when string fragments are close in space. Taking the effective nucleon radius as a free parameter, we observe for S + S at 200 GeV a percolation transition close to the physical radius of 0.8 fm.