Proton - Lambda Correlations in Central Pb+Pb Collisions at 158A GeV

Motivation The fireball created in ultra-relativistic heavy ion col- lisions is thought to form a state of deconfinement: the quark-gluon plasma (QGP). The QGP is believed to have existed fractions of seconds after the big bang and proof of it's creation and properties are of general interest. Two par- ticle correlations are widely used to investigate the dynamic evolution of the fireball. Especially pion-pion correlations allow for a multi-dimensional analysis of the parameters of the particle emitting source. Although proton-lambda correlation measurements suffer from lower statistics (thus only one-dimensionial analyses have yet been published), they provide a clean signal: only strong interaction leads to an excess of proton-lambda pairs for small momentum dif- ferences of the two particles (1). Known parameters of the final state interaction allow us to extract source sizes from correlation measurements.