Two-Particle Azimuthal Correlations in High-Energy Collisions

The angular correlations between the transverse momenta of particles preduced in high-energy collisions are studied. An explicit expression is derived for the so-called minimal azimuthal correlations, in terms of the total cross section and the single-particle distribution function. A simple model is also considered for illustration. Experimental distributions for several pi / sup +/p reactions at 8.5 GeV/c and at 20 GeV/c are presented and compared with the minimal correlations. (auth)