We report on the p T dependence of nuclear modification factors (R CP) for KS0, Λ, ≡ and the ratios at mid-rapidity from Au+Au collisions at = 39, 11.5 and 7.7 GeV. At = 39 GeV, the R CP data show a baryon/meson separation at intermediate p T and a suppression for KS0 for p T up to 4.5 GeV/c; the shows baryon enhancement in the most central collisions. However, at = 11.5 and 7.7 GeV, R CP shows less baryon/meson separation and shows almost no baryon enhancement. These observations indicate that the matter created in Au+Au collisions at = 11.5 or 7.7 GeV might be distinct from that created at = 39 GeV.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.