No abstract available

[en] The search of a short-lived neutral particle (V⁰-shaped event) has been accomplished. The experiments are carried out using a nuclear emulsion irradiated by 200 GeV/c protons. The event detected is similar to a V⁰ event by its characteristics. Invariant masses and neutral particle time-of-flight are calculated under various assumptions on the secondary particle nature

No abstract available

[en] The results of the search for short-lived particles in approximately 1800 events of interaction of 400 GeV/c protons with emulsion nuclei are given. The data on characteristics of events which can be interpreted as the decay of charged charmed particles into three charged ones are obtained. Both angular and momentum characteristics of the decay products are presented. The invariant masses of decay particles are calculated under different assumptions on the nature of the decay products. In all cases the errors of the mass definition are less than 20%

[en] The (2+0+21) p type interaction with evidently expressed two-jet production of relativistic particles is observed in nuclear photoemulsion exposed to 200 GeV proton beam. Various interpretations of this event are considered. The event microphotography image shows clearly the consequences of a hard hadron-hadron collisions when the interaction between the quarks of colliding hadrons resulted in a jet (6-particle) production under large angle with respect to the primary particle direction with a total transverse momentum of approximately 3 GeV/c

[en] A technique to separate jets among secondary particles in multiple production processes at high energies is proposed. The basic criterion is the value of relative particle density ν representing a ratio of the particle density in a solid angle containing particles of a jet to the mean density in a spherical ring with the same angular boundaries. Possibilities of the technique are discussed on the example of 800 events in the interaction of 200 GeV/c protons with emulsion nuclei at secondary particle multiplicity >= 7. The results have demonstrated that the intoduced value ν is rather convenient in separating narrow particle jets, classifying the jets and comparing data obtained by different techniques

[en] Results of search for production and decay of short-lived charged charmed particles in interactions of 400 GeV/c protons and emulsion nuclei are given. 32 secondary stars related to the primary interaction of one-charged relativistic particle have been discovered. Also 11 stars were recorded at a distance from 1000 to 3000 μm from primary. Condition and momentum characteristics of decay products of secondary events of the (0+0+3)p type are given. Invariant masses of decayed particles have been calculated on different assumptions of the decay product nature for these cases. The values obtained are close to the mass of charmed baryon for some decay schemes. Time-of-flight before decay is in the intervai of 9.3x10^-₁₄-1.6x10^-₁₂ s

[en] The recent status of the EMU01 experiment where nuclear emulsions are used as both target/detector material for horizontally exposed stacks and as detector for vertically exposed chamber plates is discussed. An investigation of the behaviour in the number of produced particles per participating nucleon reveal weak nonlinear effects for the most central collisions. Intermittency index can be obtained from the density distributions for S+Au and S+Ag interactions which corresponds to fractal dimensions somewhat smaller than unity

[en] Pseudorapidity density distributions of charged particles in heavy-ion collisions have been studied. The results from EMU01 have been compared to the results from the experiments WA80 and E802. The recently obtained pseudorapidity distributions from Au+Au and Au+Ag interactions have been compared to a linear extrapolation from lighter systems. (orig.)

[en] The EMU01 Collaboration has employed emulsion chamber and pellicle detectors to accumulate a large database of heavy nucleus interactions. Samples include both minimum bias and central collisions, analyzed in a uniform manner to extract multiplicities and angular distributions of charged particles and nuclear fragments. We find that the main features of these distributions are well represented by geometrical superposition models. A unique feature of EMU01 is the use of emulsion chambers with thin foil targets to observe produced particle angular distributions with exceptionally high precision, permitting extension of fluctuations and correlations analyses beyond the resolution limits imposed by other experimental techniques. The data are generally well reproduced by interaction simulations such as FRITIOF (the Lund monte carlo for nuclear collisions) which include only conventional physics effects. However, the analysis of fluctuations and correlations via factorial moment and cumulant techniques yields some suggestive results which require further investigation, both by continued analysis of existing data and from Au and Pb beam exposures scheduled for the next few years. (orig.)