Baryon Rapidity Loss in Relativistic Au+Au Collisions
  An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a thermal source at midrapidity decreases with increasing beam energy. 
E917 Collaboration: B. B. Back, R. R. Betts, J. Chang, W. C. Chang, C.   Y. Chi, Y. Y. Chu, J. B. Cumming, J. C. Dunlop, W. ...