Strange resonance production in heavy ion collisions at RHIC

Christina Markert

Short lived resonances are sensitive to the medium properties of a heavy ion collision, in particular the temperature, density and expansion velocity. Thermal models underpredict the yield of of K(892) and Lambda(1520) in Au+Au collisions which allows us to conclude that an extended hadronic interaction phase exists between chemical and thermal freeze-out. During this time the decay particles of resonances will re-scatter and coalesce to regenerate resonances. These mechanisms affect the resonance yield mostly in the low momentum region below 1 GeV/c. It is thus interesting to study resonances at higher momentum where the spectra of non-resonant particles exhibit effects such as enhancement through constituent quark recombination and quenching in the dense partonic medium. Strange mesonic and baryonic resonance spectra are studied at higher momentum to determine the production mechanisms in Au+Au collisions in comparison to p+p and d+Au collisions. In addition the effect of canonical suppression on the nuclear suppression factor R(AA) and R(dA) and the elliptic flow v2 for strange resonances in comparison to strange particles are investigated.