M.I. Adamovich

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.

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.

Diffractive coherent production in interactions of 400 GeV/c protons on emulsion nuclei

Abstract Data on coherent diffractive dissociation of 400 GeV/c protons on emulsion nuclei are presented. Measurements were made of total and topological cross sections as well as of cross sections of the exclusive channels p → pπ+π− and p → p2π+2π−. The energy dependence of some basic characteristics (cross sections, multiplicity of the diffractively excited system) of such reactions in the range 20–400 GeV is discussed and it is observed that these dependences are the same qualitatively for both the diffractive and non-diffractive components of multiparticle production.

Coherent Dissociation

First searches for the coherent dissociation of relativistic oxygen nuclei into four a particles are reported. It is shown that reactions of this type are characterized by a significantly lower decay temperature than the conventional multifragmentation of residual projectile nuclei. The momentum spectra and correlations of a panicles are not reproduced by the simple statistical model of direct fragmentation. The possibility that the oxygen nucleus undergoing fragmentation acquires a nonzero angular momentum in the collision process is discussed.

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New results concerning the topology of the fragmentation of relativistic nuclei 7Li and 10B are presented. A program is proposed for studying the cluster structure of stable and radioactive nuclei. The use of emulsions in the investigation of nuclear clustering in the fragmentation of light nuclei at energies are in excess of 1 GeV per nucleon is discussed.

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Abstract The interaction of relativistic deuterons with photoemulsion nuclei has been investigated. The photoemulsion method makes it possible to precisely measure small angles between relativistic particles in reactions and to select unambiguously the events of inelastic deuteron absorption. Proton stripping in the interaction of 9.38 GeV/ c deuterons has been investigated.