MEASUREMENTS OF 525 GEV PION INTERACTIONS IN EMULSION

Measurements have been made of inclusive 525 GeV pi- interactions in e mulsion. The results are compared to proton-emulsion and lower energy pion-emulsion data. Average multiplicities of relativistic shower part icles increase with increasing energy, although with a somewhat steepe r slope above 60 GeV than at lower energies. The ratio [n(s)]p/[n(s)]( pi) approximately 1.1 over the energy range 60-525 GeV. The ratio of t he dispersion in the multiplicity distribution to the average multipli city is the same for proton and pion collisions in emulsion, and is in dependent of projectile energy. The shape of the shower particle multi plicity distribution does not vary significantly with energy, and KNO scaling appears to hold over the energy range 60-525 GeV. The shower p article pseudorapidity distributions are independent of the beam energ y in the target and projectile fragmentation regions, and both the pse udorapidity and multiplicity distributions agree reasonably well with the FRITIOF model predictions for 525 GeV pions. The dependence of the shower particle multiplicity [n(s)] on the number of heavy tracks N(h ) approaches saturation as the total shower particle energy becomes a significant fraction of square-root s, and the pseudorapidity distribu tions shift toward smaller [n] with increasing numbers of grey and bla ck tracks at 525 GeV. Neither the average number [N(h)] nor the multip licity distributions of the heavily ionizing tracks vary significantly with energy, and the normalized angular distributions of grey and bla ck tracks are independent of the type of projectile or projectile ener gy.