Deuteron Flow in Ultrarelativistic Heavy Ion Reactions

Deuteron momentum distributions are predicted for nucleus-nucleus reactions at beam energies of (10–15) $A$ GeV. The deuteron transverse momentum spectra exhibit a pronounced shoulder-arm shape deviating markedly from thermal distributions due to collective transverse nuclear flow. A clear “bounceoff” event shape is seen for protons and deuterons: The transverse momentum components in the reaction plane are for deuterons up to a factor of 2 larger than for protons. The strength of the collective matter flow is sensitive to the type of baryon potential interaction employed. This allows the study of the transient mean fields at high density in these reactions via the event shape analysis of nucleons and nucleon clusters.