We have measured $〈p_{\perp }〉$ as a function of multiplicity for the reaction proton (antiproton) on proton, neon, argon, and xenon. For all reactions, $〈p_{\perp }〉$ is independent of multiplicity. We observed that the pion-emission volume is the same for both hydrogen and xenon targets and has a radius about 1.5 fm. Our analysis shows no indication of a deconfinement phase transition in nuclear matter.

• Received 18 August 1983

DOI:https://doi.org/10.1103/PhysRevD.29.363