V.G. Larionova

A study of inelastic pion-nucleus interactions at 200 GeV/c in an emulsion

Abstract Results from a study of π-nucleus interactions in emulsion, at an incident momentum of 200 GeV/c are presented and discussed. Some characteristics of heavy and shower-particle multiplicity distributions are reported and compared with the results from p-nucleus collisions at the same momentum. The angular distributions of shower particles are reported and analyzed in detail. It is shown, particularly, that one-particle distributions, being plotted in terms of pseudorapidity, have a bimodal structure in πA interactions. Also, pseudorapidity and azimuthal two-particle correlations are investigated. Considerable attention has been devoted to the exclusion of kinematical and trivial correlations. A qualitative comparison of the data with predictions of some model approaches has been performed.

Nuclear interactions of 4.5 GeV/c protons in emulsion and the cascade-evaporation model

New experimental data on proton-nucleus interactions in emulsion at primary momentum 4.5 GeV/c are presented and discussed. The data are systematically compared with predictions of the cascade-evaporation model. The directions of development of the cascade-evaporation model in a region of incident momenta are considered, and some suggestions are made for giving it more precision.

Investigation of inelastic interactions of 400 GeV protons with emulsion nuclei

Abstract The basic experimental characteristics of incoherent interactions of 400 GeV protons on emulsion nuclei, such as the multiplicity of charged secondaries, one-particle distributions and two-particle correlations, are reported and discussed in details. They are compared with the results of other experiments on hadron-nucleus interactions at lower energies. We have shown from both the quantitative and qualitative comparison of the data presented with predictions of various model approaches to nuclear production, that most of them cannot explain the complete set of experimental observations. An analysis of the experimental data presented gives strong support to the idea that the production mechanism in high-energy hadron-nucleus interactions has two or multi-component character.

A search for non-statistical particle density fluctuations in 16O + Ag(Br) and 32S + Au interactions at 200 A GeV

Abstract Fluctuations in particle densities of non-statistical origin are studied in central 16 O+Ag(Br) and 32 S+Au interactions at 200 A GeV. Non-statistical fluctuations in the 32 S-induced interactions seem to enhance the local particle densities, and suggest the presence of intermittancy. The fluctuations are found to be accompanied by a clustering tendency also in the azimuthal plane. A new method for the study of azimuthal correlations is proposed.

Energy, target, projectile and multiplicity dependences of intermittency behaviour in high energy O(Si,S) induced interactions

Fluctuations of charged particles in high energy oxygen, silicon and sulphur induced interactions are investigated with the method of scaled factorial moments. It is found that for decreasing bin size down to δη∼0.1 the EMU01 data exhibits intermittent behaviour. The intermittency indexes are found to decrease with increasing incident energy and multiplicity and to increase with increasing target mass. It seems also to increase as the projectile mass increases.

Interactions of relativistic Li-6 nuclei with photoemulsion nuclei

Inelastic interactions of nuclei accelerated to a momentum of 4.5 GeV/c per projectile nucleon with photoemulsion nuclei have been investigated. The main features of these interactions mean ranges of 6Li nuclei, mean multiplicities of secondaries, the isotopic composition of fragments, fragmentation channels, and the mean transverse momenta of projectile fragments have been measured. The probability of the charge-exchange reaction featuring lithium nuclei has been determined. The results obtained for the 6Li nucleus have been compared with data for other nuclei. The observed features of 6Li interactions with other nuclei indicate that the 6Li structure in the form of the loosely bound system consisting of an α-particle and a deuteron cluster clearly manifests itself in these interactions. Events resulting in the coherent dissociation of 6Li nuclei into 4He+d, 3He+t, and t+ d+ p and involving low-lying excitations of 6Li have been observed. DOI: 10.1134/S1063778810120161 PACS numbers: 21.45.+v, 23.60+e, 25.10.+s 1 ar X iv :1 10 9. 64 22 v1 [ nu cl -e x] 2 9 Se p 20 11

Fragmentation of 22Ne in emulsion at 4.1A GeV/c

Charge distributions of projectile fragments produced in the interactions of 22Ne beams with emulsion at 4.1A GeV/c have been studied. Correlations between projectile and target fragments and among projectile fragments are presented. The change of charge yield distribution with the violence of the collision has been shown. The present analysis contradicts theoretical calculations describing the inclusive charge yield distribution of fragments by a single process.

Multiplicities in84Kr interactions in emulsion at 800–950 MeV/nucleon

Inelastic interactions induced by84Kr nuclei at 800–950 MeV/nucleon have been studied using a high angular resolution emulsion detector. Data on multiplicities of the produced particles, projectile and target fragments are shown. Comparisons with cascade calculations have been performed.

ON THE ENERGY AND MASS DEPENDENCE OF THE MULTIPLICITY IN RELATIVISTIC HEAVY-ION INTERACTIONS

The average multiplicities of singly charged relativistic particles in oxygen-induced interactions with a nuclear emulsion target are studied over the energy range 2.1–200 A GeV. A similar energy dependence as for proton-induced interactions is observed. Both the number of participating nucleons and the number of binary collisions are shown to be of importance for the particle production.

Nuclear Clustering Quest in Relativistic Multifragmentation

The status of nuclear clustering studies performed by nuclear emulsion irradiations in beams of light relativistic nuclei is briefly reviewed. Thanks to the best spatial resolution and full solid angle acceptance provided by nuclear emulsions, such an approach allows one to obtain a unique and evident observations reflecting cluster-like features in light nuclear structures. Future investigations are suggested in relativistic beams of He, Be, B, C, and N isotopes.