Rapidity dependence of deuteron production in central Au+Au collisions at √s_NN=200 GeV

We have measured the distributions of protons and deuterons produced in the 20% most central Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) (√sNN=200 GeV) over a very wide range of transverse and longitudinal momentum. Near midrapidity we have also measured the distribution of antiprotons and antideuterons. We present our results in the context of coalescence models. In particular, we extract the "homogeneity volume" and the average phase-space density for protons and antiprotons. Near central rapidity the coalescence parameter B₂(p_T) and the space-averaged phase-space density (p_T) are very similar for both protons and antiprotons. For protons we see little variation of either B₂(p _T) or the space-averaged phase-space density as the rapidity increases from 0 to 3. However, these quantities depend strongly on p _T at all rapidities. These results are in contrast to data from lower-energy collisions where the proton and antiproton phase-space densities are different at y=0, and both B₂ and depend strongly on rapidity.