M. M. Sherif

On slow-particle production in 200A GeV16O-emulsion interactions

SummaryThe multiplicity distributions and the correlations of different types of slow particles produced in 200A GeV oxygen-induced interactions with emulsion nuclei are presented. The experimental distributions are studied within the framework of the generalized Andersson-Otterlund-Stenlund (AOS) model for nucleus-nucleus interactions. The generalized (AOS) model fails to describe the present experimental data. Also a systematic comparison using the calculations of VENUS model is made. The grey-particles multiplicity is successfully reproduced by the theoretical multistring model VENUS, while the model is inadequate for explaining the distribution of black particles.

Coulomb dissociation of incident 16O at 4.5 GeV/c

Projectile multifragment breakup of 16O, 2C and 7Li at energies 3.0–4.5 A-GeV is studied by means of the Weizsäcker-Williams method. The fragmentation channels of the 16O projectile at 4.5 A-GeV are investigated and compared with that of 16O at 200 A-GeV. The events characterized by Nh=0 and the events due to both Coulomb and diffraction dissociation have been selected and analyzed as a function of impact parameter. Also, the dependence of the electromagnetic dissociation cross-section on incident energy and the charge of projectile and target is found.

Central collisions of24Mg nuclei with heavy emulsion group of nuclei (Br, Ag) at 4.5 AGeV/c momentum

Central collisions of24Mg nuclei with the heavy (AgBr) group of emulsion nuclei are selected and analysed according to several selecting criteria. Theoretical calculations concerning cross sections for central events, average number of interacting protons from both projectile and target nuclei, multiplicity distributions of shower particles and dispersions, all based on the Glauber model, are performed to evaluate various criteria to select central events. The selection criterion based on the high multiplicity of total charged particles provides satisfactory agreement with the theoretical calculations.

Interaction of relativistic alpha particles in emulsion at 2.1 GeV/c/nucleon

An analysis for 2,000 events produced by 2.1 GeV/c/n alpha particles in nuclear emulsion has been carried out. Multiplicity and angular distributions of charged secondaries have been measured and correlation among them are discussed. The presented data are compared with relevant values from proton and14N interactions with nuclei. The multiplicity distribution of showers has been tested by a modified independent nucleon-nucleus multiple scattering model (INAM) of reference [8], and by the model of reference [12].

Multiplicity distributions of produced particles in 60A GeV16O-emulsion interactions and eclipse effect

SummaryThe shower particles multiplicity distribution produced in 60A GeV16O-Em collisions is studied in the framework of an extended Glauber model in which terms higher than the first (optical limit) in the phase shift expansion are considered. These are the so-called eclipse correction terms. The calculated distribution shows satisfactory agreement with the present experimental data.

Some characteristics of produced particles in16O-emulsion collisions at different relativistic energies

SummaryThe charged-particle multiplicities produced in inelastic interactions of16O ions at 3.7 and 60A GeV with emulsion nuclei are investigated and compared with theoretical predictions. Results from the interaction with CNO and AgBr target nuclei are analysed in terms of negative binomial (NB) distribution. Data from other nucleus-emulsion collision experiments have been used to fit an empirically proposed relationship for the average value of total charged multiplicity as a function of the geometrically determined number of interacting nucleons.

Angular production of fast and slow particles in7Li-emulsion interactions at 26 GeV

SummaryThe angular distributions of the relativistic particles emitted in the inelastic interactions of7Li-nuclei were studied in terms of the pseudorapidity variable. These distributions are fitted by Gaussian curves. The distributions are compared with the distributions obtained using12C-emulsion at similar energy and others incident beams at higher energies. The dispersion of these distributions is found to be independent of the size of the interacting systems at similar energies. The dispersions σ and the average pseudorapidities increase when the energy of the incident beam increases. The angular distributions of the emitted grey and black particles are studied in the frame of the Maxwell-Boltzmann distribution.