Characteristics of He-nucleus interactions at relativistic energy

From the peripheral collisions of28Si projectile at 14.5 A GeV in nuclear emulsion, emerged4He nuclei among the projectile fragments, are followed for their interactions. Multiplicity and pseudorapidity distributions of the produced particles emanating from 366 inelastic4He induced emulsion reactions are compared with those of28Si at 14.5A GeV,4He at 140A GeV and proton at 800 GeV beams. Standard deviation of the Gaussian fittings to the pseudorapidity distributions for different values of average shower particle multiplicities represents an approximate measure of the impact parameter. Second moments of the multiplicity distributions of the shower tracks can be parameterized in terms of a universal polynomial dependence. Results agree quite well with the predictions of the multistring model VENUS.