Figure. K/Pi ratio at mid-rapidity as a function of sqrt(s). The curves are a parameterization of the p-p data. The STAR data points are indicated by the caps and the STAR K+/pi ratio is displaced slightly to clarity.

Kaons carry ~90% of the strange quarks produced in a collision hence the K/pi ratio can be used to study strangeness production and the possibility of strangeness enhancement. As the pi⁺yield ~ pi^- yield it is possible to compare the STAR K⁺/pi^- results to lower energy results on the K⁺/pi⁺. The K^-/pi ratio can be seen to rise smoothly with sqrt(s) while that of K⁺/pi in heavy ion collisions increases sharply at low energies reaching a maximum at sqrt(s)~10GeV before slowly dropping. At sqrt(s)=130 GeV the K⁺/pi ~K^-/pi. The peak is determined by the dropping net baryon value combining with increasing K anti-K pair production. Similar behaviour is observed in the strange baryon ratios. Comparisons to the p-p data at sqrt(s)=130 GeV shows a 50% increase in the STAR (K⁺+K^-)/2*<pi> ratio.