$\Lambda$ Production at High Rapidity in d+Au Collisions at $\sqrt{s_{NN}} = 200$ GeV

Abstract

We present first preliminary studies of $\Lambda$ and $\bar{\Lambda}$ production in the pseudorapidity region $2.5 < |\eta| < 4$, covered by the forward radial-drift TPCs (FTPCs) in STAR. The FTPCs provide momentum and charge determination but no particle identification, making the use of combinatorial methods and background subtraction necessary for $\Lambda$ identification. The $\bar{\Lambda}/\Lambda$ ratio measured at high rapidity is compared to the ratio obtained at mid-rapidity with the STAR TPC. Differences in the ratio at positive and negative rapidity point to an asymmetry in particle and antiparticle production in d+Au collisions.