Energy and centrality dependence of p and p production and the {lambda}/p ratio in Pb+Pb collisions between 20A GeV and 158A GeV

• Published in: Physical review. C, Nuclear physics Nuclear physics, 2006-04, Vol.73 (4)
• Main Authors: Alt, C., Blume, C., Bramm, R., Dinkelaker, P., Flierl, D., Kliemant, M., Kniege, S., Lungwitz, B., Mitrovski, M., Renfordt, R., Schuster, T., Stock, R., Strabel, C., Stroebele, H., Wetzler, A., Anticic, T., Kadija, K., Nicolic, V., Susa, T., Baatar, B.
• Format: Article
• Language: English
• Subjects: ANTIPROTONS; CERN SPS SYNCHROTRON; DISTRIBUTION; GEV RANGE; LAMBDA BARYONS; LEAD 208 REACTIONS; LEAD 208 TARGET; MULTIPLE PRODUCTION; NUCLEAR PHYSICS AND RADIATION PHYSICS; NUCLEAR REACTION YIELD; PARTICLE RAPIDITY
• ISSN: 0556-2813; 1089-490X
• DOI: 10.1103/PhysRevC.73.044910

The transverse mass m{sub t} distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20A, 30A, 40A, and 80A GeV beam energies in the fixed target experiment NA49 at the CERN SPS. The rapidity density dn/dy, inverse slope parameter T, and mean transverse mass derived from the m{sub t} distributions are studied as a function of the incident energy and the collision centrality and compared to the relevant data on proton production. The shapes of the m{sub t} distributions of p and p are very similar. The ratios of the particle yields, p/p and {lambda}/p, are also analyzed. The p/p ratio exhibits an increase with decreasing centrality and a steep rise with increasing beam energy. The {lambda}/p ratio increases beyond unity with decreasing beam energy.