Proton and produced particle distributions from Au+Au collisions at 11.6 A GeV/c

The highest net baryon density possible in the laboratory--up to ten times normal nuclear density--is expected in the central region of collisions of heavy nuclei (A ∼ 200) at energies near 10 GeV per nucleon. The transverse energy (ET) distribution, as well as yields of identified particles (π+, K+ and protons), from 197Au + 197Au at 11.64A GeV/c are presented. Two key observations are a large degree of proton ''stopping,'' indicating multiple scatterings of the incident nucleons, and a proportional relationship of the pion production to the number of participating nucleons. Strangeness enhancement, a proposed signature of the quark-gluon plasma, is studied via the K+/π+ ratio, which achieves the value of 21% without a strong centrality dependence. Comparisons to similar data taken with a 14.6A GeV/c beam of 28Si are made