Rapidity dependence of charge particle yields for Au+Au at image GeV Original Research Article

Yields of charged particles (π±, K±, p and View the MathML source) have been derived from spectra measured with BRAHMS for the reaction Au+Au at View the MathML source GeV, as a function of rapidity in the range y = 0 to y ≈ 3 for the 10% most central events. The yields peak at mid-rapidity with a small decrease in the raange ∣y∣ ≲ 1 but they drop significantly at higher rapidities except for the protons. At y = 0, the K−/π− ratio is 0.18 ± 0.02 (syst), very close to the K+/π+ ratio equal to 0.19 ± 0.02 (syst). but at y = 3, K−/π− drops to 0.12 ± 0.02 (syst) while K+/π+ remains constant.