32S AgBr Interactions Research Articles

Pion fluctuation and its multiplicity dependence in ultrarelativistic nuclear collisions

This paper studies the multiplicity dependence of the fluctuation pattern of pions produced for 16O–AgBr interactions at 60 A GeV and 32S–AgBr interactions at 200 A GeV. We divided the data for the pions produced into four sets depending on the number of shower tracks (ns). We investigated the fluctuation pattern of emitted pions corresponding to different sets in both η (pseudorapidity) and ϕ (azimuthal angle) space. The multiplicity dependence was studied with respect to parameters αq, Dq, multifractal specific heat c, and effective fluctuation strength αeff. The study clearly indicates that the fluctuation pattern depends on multiplicity both in pseudorapidity and azimuthal angle space for 16O initiated interactions. However, for 32S initiated interactions, no multiplicity dependence is evidenced by the data in azimuthal angle space. For both, the multiplicity dependence is not very strong and significant only at large average multiplicity. Multiplicity dependence was further studied in a small window around the central pseudorapidity, and we found that multiplicity dependence is more prominent in the central region. The multiplicity dependence of αeff is more pronounced in the case of 32S–AgBr interactions than in case of 16O–AgBr interactions. PACS Nos.: 25.75–q, 24.60 Ky

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.

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.

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.

Pronounced Fluctuations of Target Fragments in ForwardHemisphere Only in Ultra Relativistic Nuclear Collision

Dynamical fluctuation of target evaporated black particles isinvestigated in both forward and backward hemispheres within theframework of multi-dimensional factorial moment methodology using thebrilliant concept of the Hurst exponent. We analyse the black particlesemitted in 32S–AgBr interactions at 200 AGeV and it isevident that the dynamical fluctuation in the backward hemisphere isself-affine. In the forward hemisphere, dynamical fluctuation isself-similar but not self-affine. However, study indicates that thefluctuation in the forward hemisphere is more pronounced than that inbackward hemisphere.

Evidence of Strong Pion Fluctuation in Jet-Like Events in32S–AgBr Interactions

We presents the analysis of ring-like and jet-like events in terms ofScaled Factorial Moments (SFMs) in one-dimensional space up to thesixth order of moments for 32S–AgBr interactions at 200 AGeVenergy. The study reveals a power law growth of SFMs withdecreasing bin width of the azimuthal distribution in the32S–AgBr data at 200 AGeV in both the cases. It is seen thatstrong intermittent pattern is revealed only in jet-like events.

Pion production and multifractality in ultrarelativistic nuclear collision – evidence of constant specific heat

Multifractal analysis of the pions produced in 32S–AgBr and 16O–AgBr interactions at 200 and 60 AGeV, respectively, is performed following the method proposed by Takagi. The generalized fractal dimensions Dq's are determined and found to decrease with order, thereby supporting multifractality in multiparticle production. From the knowledge of Dq, the multifractal specific heat is calculated for each interaction. It has been observed that the value of the specific heat is independent of the collision energy. PACS Nos.: 25.75–q, 24.60.Ky, 12.40.Ee

Multidimensional erraticity analysis in ultra-relativistic nuclear collisions

This work reports a detailed study on multidimensional erraticity analysis on 32S–AgBr interactions at 200 A GeV. A general scaling law between the erraticity moments with phase-space partition number is observed. The analysis reveals the true picture of chaotic pion production.

Non-statistical fluctuation in compound multiplicity distribution in ultrarelativistic nuclear collisions—factorial correlator study

An investigation of non-statistical fluctuation of the compound multiplicity spectrum in 32S–AgBr interactions at 200 AGeV in terms of factorial correlators is presented. It is observed that the correlated moments increase with decrease in bin–bin separation D, following a power law, which suggests the presence of an intermittent nature of self-similar dynamical fluctuation patterns in the compound multiplicity spectrum. The data also support the α model of intermittency.

Multiplicity-dependent chaotic pionization in ultra-relativistic nuclear interactions

The fluctuation of spatial patterns from event to event has been investigated by analysing the pionization data of 32S–AgBr interactions at 200 A GeV in terms of a new parameter entropy index, μq, which is a measure of chaotic behaviour in multipion production process. It is observed that the multipion production process becomes more chaotic with the increase of average multiplicities of the final states.

Evidence of Intermittent Type Fluctuation of Target Residue in Relativistic Nuclear Collisions at a Few Gev/n

This paper presents evidence of intermittency in target fragmentation in 28Si-AgBr interactions at 14.5 AGeV in emission angle space and azimuthal angle space separately and also in two-dimensional (cos θ,ϕ) space. From the intermittency exponent, the anomalous fractal dimension dq is calculated and the variation of dq with the order q is investigated. The authors also compare the results with those obtained from 16O-AgBr interactions at 60 AGeV and at 2.1 AGeV and 32S-AgBr interactions at 200 AGeV to study the energy dependence of intermittent type of fluctuations in emission angle and azimuthal angle space separately. Comparing the intermittency exponents in one- and two-dimensions it is further seen that intermittency exponent has a higher value in two-dimensional space.

Analysis of fluctuation of fluctuations in 32S–AgBr interactions at 200 A GeV

The possible signature of chaotic behavior of multiparticle production in nucleus–nucleus collision has been investigated with the help of a new parameter, the entropy index μ q . This index describes the event-to-event fluctuation of factorial moments which measures the spatial fluctuation of the multiplicity distribution. An analysis of 32S–AgBr interaction data at 200 A GeV reveals a large value for the entropy index signifying chaotic behavior of the multipion production process in ultrarelativistic nuclear interactions.

Self-affine multiplicity fluctuation of target residues in relativistic nuclear collisions at a few GeV to a few hundred GeV

Self-affine multiplicity scaling is investigated in the framework of two-dimensional factorial moment methodology using the concept of the Hurst exponent (H). Our investigation on experimental data of the target-evaporated slow particles emitted in 32S-AgBr interactions at 200 AGeV and 28Si-AgBr interactions at 14.5 AGeV reveals that a better power law behavior is exhibited in self-affine analysis than self-similar analysis. This work shows a clear evidence of self-affine target fragmentation.

Evidence of Dynamical Fluctuation of Target Residues in Relativistic Nuclear Interaction at 14.5 AGeV

An analysis of data of target fragments of 28Si-AgBr (at 14.5 AGeV) reveals the existence of emission asymmetry in the azimuthal plane, which is found to depend on the number of target fragments. The comparison with the data of 32S-AgBr (at 200 AGeV) and 16O-AgBr (at 60 AGeV) interactions indicates that emission asymmetry depends on the projectile mass and energy.

Void probability scaling in ultra-relativistic heavy ion interactions

The study of rapidity gap probability has been carried out with 32S–AgBr interactions at 200 A GeV. The study reveals the scaling behaviour of the void probability in the central rapidity domain which hints towards the outer space–inner space connection. This also confirms the validity of the linked-pair approximation for the N-particle cumulant correlation functions.

Fluctuation and fractality study of target residue in S 3 2 -AgBr interaction at 200 A GeV

In this paper we analysed scaled factorial moment in different phase-space intervals to study the dynamical fluctuation of target evaporated particles in 32S-AgBr interactions at 200 A GeV. In order to gather knowledge about the detailed characteristics of intermittency behaviour, the SFMs are calculated upto 6th order. The analysis indicates the occurence of a nonthermal phase transition and different aspects of particle production. The multifractility among target evaporated particles is also indicated by the data when analysed using the new method proposed by Takagi.