CHARGED-PARTICLE MULTIPLICITY DISTRIBUTIONS AND RESCATTERING EFFECTS IN PD INTERACTIONS AT 19 GEV-C

Inelastic topological pd cross-sections at 19 GeV/c have been determined from an exposure of the CERN 2 m bubble chamber. The total cross-section for three or more prongs was measured to be (42.4±0.3) mb. The pn charge multiplicity distribution was determined from the data by taking into account rescattering, which was found to constitute (18.5±1.5)% of the above cross-section. The average pn charge multiplicity 〈n c〉 and the average over the dispersion, 〈n c〉/D were found to be 3.53±0.12 and 1.88±0.06, respectively. This latter value indicates by comparison with results at high energies that the pn multiplicity distribution fulfills KNO scaling earlier than the corresponding pp distribution. It is found that available pn data in the energy range (12÷300) GeV fit the modified KNO scaling function of Buras et al. if a value of α of 0.39 is used. © 1979 Società Italiana di Fisica.