An investigation of the high pT strange baryon anomalies at RHIC in Au +Au collisions at sqrt(s_NN) = 200 GeV.

Matthew Lamont

Results from RHIC have shown that there is an enhanced baryon/meson ratio in the intermediate transverse momentum range (2 < pT < 6 GeV/ c) in Au+Au collisions at both sqrt(s_NN) = 130 and 200 GeV. This was initially demonstrated by measurements of the pbar/pi- ratio which was then extended in pT by the Lambda/K0s ratio. The data were successfully described by models utilising different hadronization mechanisms: those having recombination of quarks and models having an interplay between flow, jet quenching and incorporating baryon junction loops.

The strange particle data from the original Au+Au run at sqrt(s_NN) = 200 GeV gave tantalising hints that the observed enhancement of baryons was diminished by a pT of 6 GeV/c, but a lack of statistics in this range made a definitive statement impossible.

Here we present an extended analysis of identified strange baryons and mesons in Au+Au collisions at sqrt(s_NN) = 200 GeV using data obtained by the STAR experiment from the 2004 running period. The increase in statistics extends the measurement of Lambdas out to at least 7 GeV/c and K0s out to 9 GeV/c. This data allows us to place limits on the range where fragmentation is believed to be applicable and the effect of baryon dominance reduced.