Biswanath Biswas

MULTIFRACTALITY AND INTERMITTENCY STUDY OF ULTRARELATIVISTIC 32S–AgBr AND 16O–AgBr INTERACTIONS: FURTHER EVIDENCE OF A NONTHERMAL PHASE TRANSITION

This paper presents an analysis of medium energy target protons emitted in 32S–AgBr interactions at 200 AGeV and 16O–AgBr interactions at 60 AGeV in terms of scaled factorial moments up to the fifth order. The study gives evidence of a nonthermal phase transition in the 32S–AgBr data. The multifractal nature of the particle spectra has also been observed using a new method proposed by F. Takagi.

Evidence of Fractality in Proton Emission in Nucleus-Nucleus Interactions

The method of scaled factorial moments is used to study non-statistical fluctuations present in the emission process of the medium-energy protons, emitted in nucleus-nucleus interactions, in terms of their emission angle (?). The investigation has been done with our data of 24Mg-Ag/Br interaction at 4.5?GeV/c/n and 16O-Ag/Br interaction at 2.1?GeV/n. Corrections have been made for the non-uniformity of the distribution of the variable used for the purposes of analysis. A power law growth of the corrected moments with decreasing bin size suggests an intermittent behaviour in both the cases. Multifractal analysis in terms of fractal moments, Gi, has also been performed, which reveals hint of multifractality in the emission process.

Fluctuation study of pionisation in ultrarelativistic nucleus-nucleus interaction

The scaled factorial moments and the multifractal moments have been investigated in differentη-intervals to study the dynamical fluctuation of pions produced in 200 AGeV32S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process.

Analysis ofPT spectrum of projectile fragments in heavy-ion interactions. Identification of collective flow of nuclear matter

SummaryTransverse-momentum data of the projectile fragments are analysed to identify the presence of collective flow of nuclear matter in symmetric (16O-CNO at 2.1A GeV and12C-CNO at 4.5A GeV/c) and asymmetric (24Mg−AgBr at 4.5A GeV/c) heavy-ion interactions, adapting the method proposed by Danielewicz and Odyniec. A comparison of the data with Monte-Carlo-simulated values gives a positive indication of collective flow in each case.

Evidence of dynamical many-particle correlation in heavy-ion interactions at 60AGeV/c and 200AGeV/c

SummaryIn this paper we have investigated distributions of rapidity gaps between particles produced in16O-Ag/Br and32S-Ag/Br interactions at 60AGeV/c and 200AGeV/c, respectively, using as the main tool the many-particle rapidity correlation function. The experimental data have been compared with the Monte Carlo simulated values to search for true dynamical correlation in each case. The existence of many-particle correlation is observed in both cases.

EVIDENCE OF INTRA- AND INTERGROUP AZIMUTHAL CORRELATIONS IN NUCLEAR INTERACTIONS AT A FEW GeV/c

The paper presents new data on azimuthal correlations in angles between different types of secondary charged particles emitted in inelastic interactions between 24Mg nuclei with the AgBr nuclei of nuclear emulsion. Azimuthal correlations are observed in some cases of intergroup correlations, and an asymmetry is found to exist in the emission of the same type of particles. The present data is compared in some cases, with those of p-emulsion, d-emulsion, α-emulsion and 12C-emulsion interactions at 4.5 A GeV/c and 84Kr-emulsion interaction at 1.4 A GeV.