Rapidity equilibration and longitudinal expansion at RHICG. Wolschin
Institut für Theoretische Physik der Universität - Philosophenweg 16 D-69120 Heidelberg, Germany
received 10 December 2005; accepted in final form 14 February 2006
published online 8 March 2006
The evolution of net-proton rapidity spectra with in heavy relativistic systems is proposed as an indicator for local equilibration and longitudinal expansion. In a Relativistic Diffusion Model, bell-shaped distributions in central collisions at AGS energies and double-humped nonequilibrium spectra at SPS show pronounced longitudinal collective expansion when compared to the available data. The broad midrapidity valley recently discovered at RHIC in central Au + Au collisions at indicates rapid local equilibration which is most likely due to deconfinement, and fast longitudinal expansion of the locally equilibrated subsystem. A prediction is made for Au + Au at .
25.75.-q - Relativistic heavy-ion collisions.
24.60.Ky - Fluctuation phenomena.
24.10.Jv - Relativistic models.
© EDP Sciences 2006