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 invaria nt mass. Using data on pi+ p and K+p collisions at 250 GeV/c, we compa re correlation functions and normalised factorial cumulants for variou s charge combinations. Strong positive correlations are observed only at small invariant masses. The normalised cumulants for ''exotic'' [(- -), (+ +)] and ''non-exotic'' pairs (+ -) and triplets decrease in po wer-like fashion with increasing invariant mass. The mass dependence i s not incompatible with the power-law behaviour as expected in a Dual Mueller-Regge framework. Comparison with FRITIOF reveals strong disagr eements, which are due to too large production rates of resonances, su ch as rho0 and eta, and the absence of a Bose-Einstein low-mass enhanc ement in JETSET.