Rapidity Dependence of Charged Antiparticle-to-Particle Ratios in Au+Au Collisions at $\sqrt{s_{NN}}=200$ GeV

Abstract

We present ratios of the numbers of charged antiparticles to particles (pions, kaons and protons) in Au + Au collisions at $\sqrt{s_{NN}}=200$ GeV as a function of rapidity in the range $y$=0-3. While the particle ratios at midrapidity are approaching unity, the $K^{-}/K^{+}$ and $\bar{p}/p$ ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from ${\mu }_B\approx 130$MeV at $y$=3 to ${\mu }_B\approx 25$MeV at $y$=0.

4 pages, 4 figures