Z. Trka

Interaction cross sections and negative pion multiplicities in nucleus-nucleus collisions at 4.2 GeV/c per nucleon

Scanning results ofp, d, he, and12C interactions on Ta plates and in propane are presented. Inelastic cross sections are determined. They agree with geometrical models. General characteristics of pion multiplicity distributions are analyzed and compared with results from nucleon-nucleon interactions. Average multiplicities of negative pions are found to depend on the number of interacting beam nucleons.

Multiplicity, momentum and angular characteristics of π− mesons forpC,dC, αC and CC interactions at 4.2 GeV/c per nucleon

Light ion collisions with carbon target at 4.2 GeV/c/N are studied. Pion multiplicity distributions, momentum and angular spectra are analysed. These data are described in terms of models assuming independent interactions of nucleons from the projectile nucleus with the target.

Peripheral and central nucleus-nucleus collisions at 4.2 GeV/c per nucleon

Experimental data on interactions of relativistic p, d, He and C nuclei with carbon and tantalum nuclei are presented. The data come from the 2−m propane bubble chamber with an internal tantalum target. It is found that interaction cross sections for carbon projectile fragments with chargesZ=5,6 are 10% greater than expected. In central C+C collisions and in multinucleon interactions of d, He and C with tantalum a contribution is observed from cumulative interactions irreducible to the superposition of NN-collisions taking into account final state interactions, rescattering effects, etc.

Multiplicity, momentum and angular distributions of protons from the interactions ofp, d, α andC with carbon at 4.2 GeV/c/nucleon momentum

Average multiplicity of protons fromp, d, α andC interactions with carbon at 4.2 GeV/c/ N is shown to increase with the mass number of incident nucleus. ThisA dependence is stronger for fast protons than for the slow ones. Angular and momentum distributions are described by the Dubna Cascade Model. Some discrepancy is observed in the high momentum part of the distributions.