Fast helium production in interactions of 3.7 A GeV 24Mg with emulsion nuclei
South Valley University, Sohag, Egypt
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Accepted: 19 July 2004
Published online: 19 November 2004
We have studied the properties of the relativistic helium fragments emitted from the projectile in the interactions of 24Mg ions accelerated at an energy of 3.7 A GeV with emulsion nuclei. The total, partial nuclear cross-sections and production rates of helium fragmentation channels in relativistic nucleus-nucleus collisions and their dependence on the mass and energy of the incident projectile nucleus are investigated. The yields of multiple helium projectile fragments disrupted from the interactions of 24Mg projectile nuclei with hydrogen H, light CNO and heavy AgBr groups of target emulsion nuclei are discussed and they indicate that the breakup mechanism of the projectile seems to be independent of the target mass. Limiting fragmentation behavior of fast-moving helium fragments is observed in both the projectile and target nuclei. The multiplicity distributions of helium projectile fragments emitted in the interactions of 24Mg projectile nuclei with the different target nuclei of the emulsion are well described by the KNO scaling presentation. The mean multiplicities of the different charged secondary particles, normally defined shower, grey and black ( 〈n s〉, 〈n g〉 and 〈n b〉) emitted in the interactions of 3.7 A GeV 24Mg with the different groups of emulsion nuclei at different ranges of projectile fragments are decreasing when the number of He fragments stripped from projectile increases. These values of 〈n i〉 ( i = s, g, b and h particles) in the events where the emission of fast helium fragments were accompanied by heavy fragments having Z ⩾ 3 seem to be constant as the He multiplicity increases, and exhibit a behavior independent of the He multiplicity.
PACS: 29.40.Rg Nuclear emulsions – / 25.75.-q Relativistic heavy-ion collisions – / 25.70.Mn Projectile and target fragmentation – / 25.70.Pq Multifragment emission and correlations –
© Società Italiana di Fisica and Springer-Verlag, 2004