D ec 2 00 4 Λ Production at Forward and Backward Rapidity in d + Au Collisions at √ s NN = 200 GeV

Using the forward time projection chambers of the STAR experiment at the Brookhaven Relativistic Heavy Ion Collider we measure the centrality dependent Λ and ¯ Λ yields and inverse slope parameters in d+Au collisions at forward and backward rapidities y = ±2.75. The contributions of different processes to stopping and baryon transport are probed exploiting the inherent asymmetry of the d+Au system. Comparisons to model calculations show that the baryon transport on the deuteron side is due to multiple collisions of the deuteron nucleons with gold participants. On the gold side, the inclusion of inital state nuclear effects or hadronic rescattering is necessary to describe the data.