Two-Particle Quantum-Number Correlations in 400-GeV/cProton-Nucleus Collisions

We have measured two-particle quantum-number correlations in 400-GeV/c proton-nucleus collisions. A double-arm spectrometer was used to detect two charged particles produced near rapidity $y_{\mathrm{c}.\mathrm{m}.\mathrm{}}=-0.4\mathrm{}$ in the proton-nucleon center-of-mass system. In proton-beryllium collisions we observe positive $p\overline{p}$ and $K^{+}{K}^{-}$ correlations which are independent of the transverse momenta of the particles over the range $1<~p_{\perp }<~1.8$ GeV/c. These correlations are weaker in proton-lead interactions.