Abstract
Rapidity spectra for protons at SIS, AGS and SPS energies are analyzed within a Relativistic Diffusion Model. At low beam energies of 1.06 A GeV rapidity diffusion coefficients are related to the corresponding relaxation times via a weak-coupling dissipation-fluctuation theorem. At higher energies progressively larger deviations are found, rising to about an order of magnitude at SPS energies.