Transverse flow and collectivity in ultrarelativistic heavy-ion collisions.

The detectability of collective transverse flow is discussed for CERN superproton synchrotron energies in Pb+Pb collisions. Calculations with a quark-gluon string model suggest there will be measurable flow in Pb+Pb reactions but not in S+S reactions at 160 GeV. Calculations of transverse flow with a fluid-dynamic model show a strong dependence on the equation of state and that the amount of flow is significantly larger than in the string model.