An update from STAR—using strangeness to probe relativistic heavy ion collisions

An overview of the strangeness measurements made by the STAR collaboration at RHIC for Au–Au collisions at <MATH ALT=""/> and 200 GeV plus p–p collisions at <MATH ALT=""/> GeV is presented. A wealth of information has been generated on the kinematics and scale of strange particle production by this experiment. When viewed in combination a picture emerges of particles demonstrating a surprisingly high degree of collective motion, suggestive of strong internal pressure within the source which builds up rapidly. The non-resonance yields are consistent with statistical hadron formation. Although there appears to be a rapid decoupling of the source, resonance particle measurements show signs of rescattering during the hadronic phase. Meanwhile the observed suppression of high momentum probes and their large azimuthal asymmetry indicate that this hot dense matter has significant interactions with particles moving through it.