K/π ratio from high-energy heavy-ion collisions

In an expanding fireball model, we determine the K/π ratio from heavy-ion collisions at 14.5 GeV/nucleon available from the Brookhaven AGS. Assuming the formation of a quark-gluon plasma in the initial stage, we obtain ratios of ≅ 23% and ≅ 5% for K+/π+ and K-/π-, respectively, which are comparable to the measured values. In the absence of quark-gluon plasma formation, the resulting K-/π- ratio has about the same value but the K+/π+ ratio is about a factor of two smaller than the measured value. (orig.)