The yields and average transverse momenta of pions, kaons, and antiprotons produced at the Fermilab $\overline{p}p$ collider at $\sqrt{s}=300, 540, 1000, \mathrm{and} 1800$ GeV are presented and compared with data from the energies reached at the CERN collider. We also present data on the dependence of average transverse momentum $〈p_t〉$ and particle ratios as a function of charged particle density $\frac{d{N}_c}{d\eta }$; data for particle densities as high as six times the average value, corresponding to a Bjorken energy density 6 GeV/${\mathrm{fm}}^3$, are reported. These data are relevant to the search for quark-gluon phase of QCD.

• Received 21 September 1992

DOI:https://doi.org/10.1103/PhysRevD.48.984