Correlation studies for high energy collisions

Phenomenology of correlation data in high energy collisions is discussed. All moments of a correlation function are determined by the second moment in the limit of weak correlations, and the prediction of independent superposition is that correlation functions vary as 1/(dN/dy), where dN/dy is the single-particle density. All current data from leptonic and hadronic scattering follow the same independent superposition prediction reasonably well. Nuclear collision data also follow the independent superposition prediction; however, the observed correlations are an order of magnitude larger in the nuclear collisions than for leptons and hadrons, and cannot be explained without the assumption of new physics. Finally, correlation analysis is discussed using the split-bin correlation functions, in order to determine the new physics behind these anomalously strong nuclear correlations. (K.A.) 12 refs