Proton - Nucleus Interactions at 200-GeV/c

The investigation of interactions of hadrons with the nucleus in recent time became very important, and there is a hope that it can give the information about the systems produced in this process (lifetime, cross sections etc.) The nuclear photoemulsions are a good detector at the investigation of hadron-nucleus interactions due to a high spatial resolution and a possibility of detection of particles nearly at all energies that enables to study the characteristics of both fast and slow particles. The consistence of emulsion enables to obtain the characteristics of interactions both on light (CNO, <A> = 14) and on heavy(Ag,Br,<A> = 94) nuclei

Yields and transverse momenta of the 6^6Li fragments in the emulsion at 4.5 GeV/c per nucleon

We present the results of the study of interaction of the relativistic $^{6}Li$ nucleus with the momentum 4.5 GeV/c per nucleon with the photoemulsion. Yields of the $^{1}H$ ($^{3}He$) and $^{2}H$ ($^{4}He)$ isotopes due to the fragmentation of $^{6}Li$ are found to be almost equal. Cross sections for the charge exchange and pickup reactions are found to be $\sigma_{exch}=9\pm2$ mb. The distributions of the fragment transverse momenta projected onto the emulsion plane are used to obtain the nucleon Fermi momentum of $^{6}Li$, $P_{F}$, this value being equal to $129\pm8$ MeV/c. The high momentum component in the transverse momentum distributions of $^{3}He$ and $^{4}He$ isotopes is observed

Multiplicity of Charged Particles in Pion - Nucleus Interactions in an Emulsion at 200-GeV/c

The experimental data on multiplicities of charged secondaries produced in pion-nucleus interactions in an emulsion at 200 Gev/c and correlations bet6ween them are presented and discussed. Parameters of multiplicity distributions are compared with the relevant ones at lower energies and with data from pA-interactions at 200 Gev/c. The multiplicity of heavily ionizing particles in {Pi}{sup -}A-interactions weakly depend on the incident energy. The KNO scaling is observed being the same for incident protons and pions

An Analysis of Angular Distributions of Relativistic Particles in Inelastic Pion - Nucleus Collisions at 200-GeV/c

General parameters characterizing single particle inclusive distributions of shower particles and their dependence on the multiplicity are discussed in {Pi} interactions at 200 Gev. The qualitative comparison of data presented with predictions of several popular models for hadron nucleus collisions are performed

A Study of Two Particle Correlations in Inelastic Pion - Nucleus Interactions at 200-GeV/c

Pseudorapidity and azimuthal two-particle correlations have been investigated in pion-nucleus interactions at 200 Gev/c. The considerable attention has been devoted to the exclusion of kinematical and pseudo-correlations. The qualitative comparison of experimental results with some theoretical models has been performed

Multiplicity of Charged Secondaries in Interactions of Protons in an Emulsion at 400-GeV/c

The preliminary results on multiplicities of charged secondaries in proton-nucleus interactions at 400 Gev/c are presented. Multiplicity of produced particles is consistent in the first approximation with the KNO scaling hypothesis for hadron-nucleus interactions. The relations between different moments of multiplicity distribution in proton-nucleons interactions at high energies are discussed too

Coherent Production of Charged Particles on Nuclei by 400-GeV/c Protons

Topological cross sections {delta}{sub coh}{sup (n)} (n = 1,3,5 and 7) of coherent diffractive dissociation of 400 Gev/c protons on nuclei of photoemulsion elements have been measured. Topological cross sections increase in the energy range from 20 to 400 Gev/c. This growth is the most noticeable for multiprong topologies. The total cross section of diffractive coherent production also increases from 8 to 25 mb/nucleus in this energy range. The increasing of the average multiplicity of charged particles in reaction of coherent proton dissociates is consistent with the logarithmic law <n>{sub coh} = (90.25 {+-} 0.05) inp. + (1.3 {+-} 0.25)

INTERACTIONS OF 200-GeV/c PROTONS WITH EMULSION NUCLEI, CHARGED PARTICLE MULTIPLICITIES

The experimental data on the multiplicity distributions for various kinds of secondaries produced in the proton-nucleus interactions in emulsion at 200 GeV/c and the correlations between them are presented and discussed. All the characteristics of heavy prongs (mean values <n{sub b}>, <n{sub g}>, <N{sub h}>, their distributions and correlations) are independent (or have a very weak dependence) on the collisions energy in the range 20-200 GeV/c. The data contradict to the cascade-evaporation model and qualitatively agree with the mechanism of particle emission via the long-lived intermediate states. The observed weak A-dependence ({approx} A{sup 0.15}) of shower particle distributions is in agreement with the calculated ones according to the simplified two-step model. It is shown that the n{sub s}-distributions agree well with KNO scaling law in the 67-200 GeV/c range, but the form of universal {psi}(n{sub s/n{sub s}})-function has a weak A-dependence