Midrapidity Λ and Λ̄ production in Au + Au collisions at √sNN = 130 GeV

We report the first measurement of strange (Λ) and antistrange (Λ¯¯¯) baryon production from √(sNN)=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at midrapidity are presented as a function of centrality. The yield of Λ and Λ¯¯¯ hyperons is found to be approximately proportional to the number of negative hadrons. The production of Λ¯¯¯ hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models alone.