Study of inelastic interactions of 340-GeV/c pions with emulsion nuclei

Results from a study of interactions of a 340-GeV/c π- beam with emulsion nuclei at the CERN SPS are presented. Some characteristics of heavy- and shower-particle multiplicity distributions are reported. The Koba-Nielsen-Olesen scaling hypothesis has been tested. Single-particle pseudorapid- ity distributions and rapidity-gap distributions have been studied in detail. The pseudorapidity distributions show a bimodal structure in all π-A interactions and the rapidity-gap distributions indicate the production of clusters during the multiparticle production process. The production of heavy clusters has also been studied using the rapidity-interval method proposed by Adamovich et al. The result shows that 340 GeV is belgical-model predictions for this ratio in nuclear matter are approx. =10-10. Any comparison of these two values assumes no mass fractionation has occurred in the geophysical disposition and subsequent extraction of the sodium forming the atomic beam and also no differences in the distribution of heavy isotopes among the elements, compared to normal isotopes, during their astrophysical formation. Making these assumptions enables limits to be placed on the heavy-particle annihilation cross sections in the formation process