<pt> Systematics and mt-Scaling
  An enhancement in the number of strange particles produced in relativistic heavy ion collisions is expected to coincide with the formation of a deconfined state of partonic matter. Measurements of transverse momentum spectra for strange particles emerging from p+p collisions are used as a baseline to which similar measurements from heavy ion collisions are compared. In addition, several observations from p+p collisions, such as the variation of <pt> with particle mass and with event multiplicity, are interesting in their own right. We present measurements of the transverse momentum spectra and <pt> systematics for strange and non-strange particles from p+p collisions at sqrt{s}=200 GeV. We show the dependence of the <pt> on measured charged multiplicity and on particle mass. We will also demonstrate the ability to scale the transverse mass spectra of various species onto a single universal curve for our p+p data (an effect known as mt-scaling) and the failure of this scaling when applied to our Au+Au data. The work presented here was presented as a poster at Quark Matter 2004. 
Richard Witt (1) (for the STAR Collaboration) ((1) LHEP, University of   Bern, Switzerland)