Strange antiparticle-to-particle ratios at mid-rapidity in √sNN=130 GeV Au+Au collisions

Values of the ratios in the mid-rapidity yields of (Lambda) over bar/Lambda = 0.71 +/- 0.01(stat.) +/- 0.04(sys.), (Xi) over bar (+)/Xi(-) = 0.83 +/- 0.04(stat.) +/- 0.05(sys.), (Omega) over bar (+)/Omega(-) = 0.95 +/- 0.15(stat.) +/- 0.05(sys.) and K+/K- = 1.092 +/- 0.023(combined) were obtained in central,rootS(NN) = 130 GeV Au + An collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over antihyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models. (C) 2003 Published by Elsevier B.V.