Madhumita Lahiri

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.

Higher order correlation of the pions and their target excitation dependence in relativistic and ultrarelativistic nuclear collisions

The target excitation dependence of higher order correlation of the pions is investigated in the present work using the data of 16O–AgBr interactions at 2.1 and 60 A GeV and 32S–AgBr interactions at 200 A GeV. The data are divided into different sets of ng which correspond to different degrees of the target excitation. The target excitation dependence was evident at the lower projectile energy—at the higher projectile energy no target excitation dependence was revealed by the data.

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.

Evidence of azimuthal void probability scaling in relativistic and ultra relativistic nuclear interactions

A study of azimuthal angle void probability of produced pions has been carried out in relativistic and ultra relativistic nucleus–nucleus interactions (32S–AgBr interactions at 200 A GeV, 16O–AgBr interactions at 60 A GeV , 24Mg–AgBr interactions at 4.5 A GeV and 12C–AgBr interactions at 4.5 A GeV). The study reveals a very interesting observation-void probability showing scaling behaviour at significantly lower energy (24Mg–AgBr interactions at 4.5 A GeV and 12C–AgBr interactions at 4.5 A GeV) whereas the behaviour is not so pronounced at higher energy in 16O–AgBr interactions at 60 A GeV and the data do not reveal scaling behaviour at all in case of 32S–AgBr interactions at 200 A GeV.

Chaos analysis of nuclear fragments in high energy collisions

This paper deals with fixed target AGS and SPS data of beam energies 14.5 and 200 A GeV respectively. A detailed study on chaos in the nuclear fragmentation process of 28Si–AgBr interactions at 14.5 A GeV and 32S–AgBr interactions at 200 A GeV has been performed using a new parameter, the entropy index. The analysis provides new data on the evidence of the erratic behavior of the target fragments signifying chaotic target fragmentation and also quantify the measure for chaos in high and ultra-high energy heavy-ion interactions. Further, it is also observed that the target fragmentation process becomes less chaotic with the increase of average multiplicities of the final states.

FLUCTUATION PATTERN OF SHOWER AND COMPOUND MULTIPLICITY DISTRIBUTIONS IN NUCLEUS–NUCLEUS INTERACTIONS AT A FEW GeV

This work presents a study on the multiplicity distribution of shower and compound multiplicity (pions + target protons) emitted from 12C–AgBr and 24Mg–AgBr interactions at 4.5 AGeV in terms of negative binomial distribution (NBD) and also on the fluctuation pattern of shower and compound multiplicity in the frame work of two-dimensional factorial moment methodology using the concept of Hurst exponent.

VALIDITY OF NAKAMURA–KUDO SCALING OF CHARGED PARTICLE PSEUDORAPIDITY DISTRIBUTION IN RELATIVISTIC HIGH-ENERGY h–A INTERACTIONS

Nakamura and Kudo proposed a scaling form for charged particle pseudorapidity distributions on the basis of scaling in the mean hypothesis. This scaling form was tested primarily for hadron–hadron interaction data. But no attempt was made to verify this for hadron–nucleus interaction which offers unique opportunity to learn about the space–time structure of a strongly interacting process. In view of this we report an analysis of p–AgBr interaction data at 400 GeV/c and 200 GeV/c, π-–AgBr interaction data at 200 GeV/c and 350 GeV/c to test its (Nakamura–Kudo scaling) validity in hadron–nucleus interaction. In all cases the data show a remarkable agreement with the scaling behavior of Nakamura and Kudo.

Multiparticle production in nucleus-nucleus interaction at 2.1 GeV/n and 200 GeV/n. Four-momentum transfer analysis

SummaryThis paper presents an analysis of the four-momentum transfer between the fireballs in the events produced in16O-AgBr interactions at 2.1AGeV and 60AGeV, and32S-AgBr interaction at 200A GeV. It also reveals the correlation between average four-momentum transfer and multiplicity of shower particles, and also the distribution of four-momentum transfer.

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.

Fractal study of pionisation in p-AgBr interaction at 400 GeV/c

SummaryIn this paper we present the fractal momentGq analysis of the produced pions in p-AgBr interaction at 400 GeV/c. The analysis reveals the multifractality of pionisation at this energy. The scaling behaviour of theseGq moments has also been studied.