Characteristics of He-nucleus interactions at relativistic energy

Abstract

From the peripheral collisions of 28Si projectile at 14.5A GeV in nuclear emulsion, emerged 4He nuclei among the projectile fragments, are followed for their interactions. Multiplicity and pseudorapidity distributions of the produced particles emanating from 366 inelastic 4He induced emulsion reactions are compared with those of 28Si 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. PACS: 25.70.Np; 12.38.Mh 292 3. Discussion of results

A study of the energy dependence for the multiplicity of shower particles produced in a 16O–emulsion interaction in the framework of the Coulomb-modified Glauber model

“…In the interaction of high-energy hadrons or nuclei with a target nucleus, the multiparticle production is considered as a two step process [12,13]. In the first part, the interacting hadrons or nuclei may participate only in the primary reaction and then these product particles leave the projectile-target overlap region without any more interactions.…”

“…In this theory the scattering amplitude is expressed in terms of an optical phase shift function, which is expanded in a series, the terms of which describe the different multiple-scattering processes. For these elements we shall consider two different chemical compositions [12,20], according to the incident energy: 0.2, 2.1, 3.6, 14.6, 60.0, and 200.0A GeV. For these elements we shall consider two different chemical compositions [12,20], according to the incident energy: 0.2, 2.1, 3.6, 14.6, 60.0, and 200.0A GeV.…”

Study of Projectile Helium (Z = 2) Fragments Produced in Nucleus–Nucleus Interactions at 14.6 A GeV

“…However, a number of other interesting aspects in heavy ion physics can be studied in the peripheral collisions. [5][6][7] In such heavy ion collisions, nucleons of the spectator parts of projectile nucleus do not interact strongly and they form the residual nuclear systems, projectile helium fragments are part of these nuclear systems. As these relativistic projectile helium fragments are the major part of the projectile fragments and also they carry the rapidity of the projectile beam so they can provide us the necessary information about the fragmentation mechanism of heavy ion nucleus-nucleus collisions.…”