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

Values of the ratios in the mid-rapidity yields of λ̄/λ = 0.71 ± 0.01(stat.) ± 0.04(sys.), ξ̄ ⁺/ξ^- = 0.83 ± 0.04(stat.) ± 0.05(sys.), Ω̄⁺/Ω^- = 0.95 ± 0.15(stat.) ± 0.05(sys.) and K⁺/K^- = 1.092 ± 0.023(combined) were obtained in central √S_NN = 130 GeV Au + Au 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.