Inclusive Lambda Baryon Spectra in Au+Au Collisions at sqrt(S_{NN}) = 200 GeV

Abstract

Studies of the lambda and anti-lambda baryons in Au+Au collisions provide information on in-medium energy loss and hadronization mechanisms, which are important to understanding the quark-gluon plasma created in ultra-relativistic heavy ion collisions. A combination of high statistics and new methods of analysis enable a study of lambda baryons to much greater p_{T}, 7 GeV/c, than was possible in previous studies at PHENIX. During the Au+Au RHIC run in 2007 the PHENIX experiment acquired over 5 billion minimum bias events at sqrt(S_{NN}) = 200 GeV. This large data set has the additional benefit of a new time-of-flight detector with approximately 70 ps intrinsic timing resolution. Lambda and anti-lambda spectra, nuclear modification factor R_{CP}, and relative particle abundances are presented. The results presented agree, within uncertainties, with published data and support the notions of both quark degrees of freedom in the quark-gluon plasma and of hadronization models that include recombination as a leading source of baryon production through intermediate p_{T}.