Physics and Astronomy
Journal or Book Title
Physical Review C
The centrality dependence of transverse momentum distributions and yields for pi(+/-),K+/-,p, and (p) over bar in Au+Au collisions at roots(NN)=200 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider. We observe a clear particle mass dependence of the shapes of transverse momentum spectra in central collisions below similar to2 GeV/c in p(T). Both mean transverse momenta and particle yields per participant pair increase from peripheral to midcentral and saturate at the most central collisions for all particle species. We also measure particle ratios of pi(-)/pi(+), K-/K+, (p) over bar /p, K/pi, p/pi, and (p) over bar/pi as a function of p(T) and collision centrality. The ratios of equal mass particle yields are independent of p(T) and centrality within the experimental uncertainties. In central collisions at intermediate transverse momenta similar to1.5-4.5 GeV/c, proton and antiproton yields constitute a significant fraction of the charged hadron production and show a scaling behavior different from that of pions.
American Physical Society
Adler, S. S.; Belikov, Sergey; Bhagavatula, S.; Constantin, Paul; Grau, Nathan C.; Hill, John C.; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Rak, Jan; Rosati, Marzia; Wohn, F. K.; et al.; and PHENIX Collaboration, "Identified charged particle spectra and yields in Au plus Au collisions at root(SNN)=200 GeV" (2004). Physics and Astronomy Publications. 381.