Antideuteron Production in High Energy Heavy Ion Collisions

Experiment E858 at the Brookhaven National Laboratory Alternating Gradient Synchrotron has recently reported the detection of two antideuterons produced in $14.6A$ GeV/c Si + Au collisions. The data were interpreted as implying antideuteron production rates about an order of magnitude below expectations. We use an extended RQMD model to demonstrate that the antideuteron yields are readily explained in a dynamical scenario that includes collective expansion and strong antinucleon absorption.