Transverse energy production and the equation of state of nuclear matter

In nuclear collisions of Au + Au, Nb + Nb and Ca + Ca bombarding energies between 150 and 800 MeV per nucleon, transverse energy and transverse momenta of light particles are studied event by event at θ = 900 in the center of mass system. At all energies, a rise of the mean transverse energy per nucleon is observed with increasing charged particle multiplicity. Particularly large values of Ε/sub perpendicular/ have been found for /sup 3/He-fragments. The hydrodynamical picture is discussed for a possible separation of the collective flow and the thermal parts of the Ε/sub perpendicular/-spectrum. From this evidence for a rather stiff equation of state is found