Invariant Mass Dependence of Particle Correlations in Pi(+)P and K(+)P Interactions at 250 Gev/C

We study two- and three-particle correlations as a function of invariant mass. Using data on π+p andK+p collisions at 250 GeV/c, we compare correlation functions and normalised factorial cumulants for various charge combinations. Strong positive correlations are observed only at small invariant masses. The normalised cumulants for “exotic” [(−−), (++)] and “nonexotic” pairs (+−) and triplets decrease in power-like fashion with increasing invariant mass. The mass dependence is not incompatible with the power-law behaviour as expected in a Dual Mueller-Regge framework. Comparison with FRITIOF reveals strong disagreements, which are due to too large production rates of resonances, such as ρ0 and η, and the absence of a Bose-Einstein low-mass enhancement in JETSET.