Rapidity dependent $K/\pi$ ratios in Au+Au collisions at $\sqrt{s_{NN}}$ = 62.4 GeV

Abstract

We report on measurements of identified particle yields from Au-Au collisions at $\sqrt{s_{NN}} = 62.4$ GeV made with the BRAHMS spectrometer. Here we will concentrate on the charged $K/\pi$ ratios as function of rapidity and baryo-chemical potential. We find that the $K/\pi$ ratios measured at different rapidities in the analysed dataset have a common dependence with the same ratios measured in mid-rapidity at SPS energies when plotted as function of the $\bar{p}/p$ ratio. The theoretical models used for comparison, UrQMD and AMPT, give a reasonable description of the particle yields at mid-rapidity but fail to do so for the $K/\pi$ ratios at forward rapidity.