Relativistic diffusion model

G. Wolschin

doi:doi:10.1007/s100500050260

EPJ

Relativistic diffusion model

G. Wolschin

Keplerstrasse 30, D-69120 Heidelberg, Germany

Received: 24 November 1998 / Revised version: 20 February 1999 Communicated by B. Povh

Abstract
Evidence is presented that diffusion drives colliding many-particle systems at relativistic energies from the initial $\delta$ -functions in rapidity towards the equilibrium distribution. Analytical solutions of a linear Fokker-Planck equation represent rapidity spectra for participant protons in central heavy-ion collisions at SPS-energies accurately. Thermal equilibrium in the interaction region is not attained, nonequilibrium features persist and can account for the broad rapidity spectra.