G.M. Chernov

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.

Interactions of relativistic nitrogen nuclei in an emulsion at 2.1 GeV/nucleon

Abstract An analysis of multiple production induced by 2.1 GeV/n 14 N ions in nuclear emulsions is presented. Multiplicity and angular distributions of charged secondaries and correlations among them are discussed. The presented data are compared with relevant values from proton-nucleus interactions. The possible appearence of collective phenomena in nucleus-nucleus interactions is discussed.

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.

Fragmentation of relativistic 56Fe nuclei in emulsion

Experimental data on general characteristics of projectile fragments in inelastic interactions of relativistic 56Fe nuclei in emulsion (multiplicities, transverse momentum distributions, azimuthal correlations) are presented and discussed. A strong dependence on the mass number of the projectile nucleus is observed for the transverse momenta of the emitted projectile fragments. These fragments exhibit an azimuthal asymmetry caused by the transverse motion of the fragmenting residue, but it is shown that this motion can be responsible only for a part of the increase in the average transverse momentum of the fragments with increasing mass of the projectile.

Is the “tube” approach to multiple production on nuclei credible?

Abstract The tube models of nuclear production are questioned by pointing out that they cannot explain the dependence of the inclusive rapidity distribution width and the two-particle correlation function on the atomic number of the target nucleus.

Inclusive two-and three-particle rapidity correlations in high-energy hadron-nucleus collisions

Abstract Three-particle pseudorapidity correlations are investigated for relativistic secondaries from proton-nucleus interactions at 50, 67, 200 and 400 GeV/c and from pion-nucleus interactions at 50 and 200 GeV/c. The experimental data on two- and three-particle correlations are compared with quantitative predictions of current multiple scattering models of nuclear production. Within these models the influence of various factors on the magnitude of correlations is discussed and it is shown, in particular, that energy-momentum conservation plays an essential role at present accelerator energies.

Coherent production of particles by 67 GeV/c protons on emulsion nuclei

Abstract In the study of interactions of 60 GeV/c π− mesons in nuclear emulsion some peculiarities of the prong-number distribution and the angular distribution of secondaries have been observed. They are interpreted in terms of the coherent production of three and five pions on emulsion nuclei. The cross section for these reactions increases with the increasing energy.

The multiple scattering model analysis of high energy multiparticle production on emulsion nuclei

Data on multiparticle production on emulsion nuclei in the range 50–400 GeV/c have been analyzed in the framework of multiple scattering model developed by Capella and Krzywicki. It is shown that under some reasonable assumptions multiple scattering type models qualitatively reproduce multiplicity distributions of relativistic charged particles, one-particle spectra and two-particle inclusive correlations.When considering one-particle distributions a particular attention was given to the regions of small and large pseudorapidities. In the first region we found an apparent evidence for low-energy cascading, contribution and main features of which have been discussed. It is also discussed how strongly the behaviour of one-particle spectra at large rapidities would depend on the internal structure of a projectile particle.

Inclusive rapidity distributions in hadron-nucleus interactions and the parton-cascade model

Abstract We present the new experimental data on inclusive production in hadron-nucleus interactions in the Fermilab energy range which do not show the specific limiting predicted by the parton model with the contribution of fan type diagrams.