Open Access

Raffaele Mattiello, Heinz Sorge, Horst Stöcker, Walter Greiner

• A phase space coalescence description based on the Wigner-function method for cluster formation in relativistic nucleus-nucleus collisions is presented. The momentum distributions of nuclear clusters d,t and He are predicted for central Au(11.6AGeV)Au and Si(14.6AGeV)Si reactions in the framework of the RQMD transport approach. Transverse expansion leads to a strong shoulderarm shape and di erent inverse slope parameters in the transverse spectra of nuclear clusters deviating markedly from thermal distributions. A clear bounce-o event shape is seen: the averaged transverse flow velocities in the reaction plane are for clusters larger than for protons. The cluster yields particularly at low pt at midrapidities and the in-plane (anti)flow of clusters and pions change if suitably strong baryon potential interactions are included. This allows to study the transient pressure at high density via the event shape analysis of nucleons, nucleon clusters and other hadrons.