Multifractal characteristics of multiparticle production in heavy-ion collisions at SPS energies

Khan, S.; Ahmad, Shakeel

doi:10.1142/s0218301318500040

“…These events are taken from the series of experiments carried out by EMU01 collaboration [23,24,25,26]. All the relevant information about the data, like selection of events, track classification, extraction of AgBr group of events, method of measuring the angles of relativistic charged particles, etc., may be found elsewhere [2,6,15,17,27,28].…”

Section: Details Of the Datamentioning

confidence: 99%

Event-by-event fluctuations clusterization and entropy production in AA collisions at AGS and SPS energies

Ali

¹

,

Khan

²

,

Chandra

³

et al. 2019

Int. J. Mod. Phys. E

Self Cite

View full text Add to dashboard Cite

Event-by-event (ebe) fluctuations in mean pseudorapidity values of relativistic charged particles in full phase space is studied by analysing experimental data on 16 O − AgBr collisions at 14.5A, 60A, and 200A GeV/c and 32 S − AgBr collisions at 200A GeV/c. The findings are compared with the prediction of A Multi-Phase Transport(AMPT) model and those obtained from the analysis of correlation free Monte-Carlo events. Fluctuations in mean pseudorapidity distributions are noticed to be in excess to that expected from the statistically independent particle emission. The observed dependence of the fluctuation strength measure parameter,φ on the beam energy and number of participating target nucleons indicate that nucleus-nucleus collisions can not be treated as simple superposition of multiple nucleon-nucleon interactions. Presence of clusters or jet-like phenomena in multihadron final states are searched for on ebe basis by using the concept of Jaynes Shannon entropy. The findings indicate the presence of cluster like objects in the experimental data with their size and frequency increasing with increasing beam energy. These observations, in turn suggest that the clustering or jet-like algorithm adopted in the present study may be used as a tool for triggering different classes of events. * Shakeel.Ahmad@cern.ch

show abstract

“…For example, when entropy concerns energy loss and is applied to explain thermodynamic principles, it is termed as thermodynamic entropy, when it concerns data loss, it is known as information entropy (or Shannon's entropy) [20], similarly, Hartley's entropy (which precedes Shannon's entropy) [21] and R´enyi's entropy (generalization of Shannon's entropy) [22]. High energy physicists [23][24][25][26][27][28][29][30][31][32] have intensively used the science of entropy to investigate the possibility of the occurrence of the formation of Quark-Gluon-Plasma (QGP) and to get a better understanding of the underlying mechanism of multi-particle process in high energy nuclear collisions (also often referred to as multifractal entropy). In reality, the study of entropy is important not only in the search for the development of QGP states but also in studying correlations and event-by-event variations.…”

Section: Multifractal Entropy and Csh-approximationmentioning

confidence: 99%

“…The thermodynamical picture of multi-particle production in high energy relativistic nuclear collisions can be very well understood by extracting a basic quantity, the multifractal specific heat, 'c' in terms of and T q moments [3][4][5] for both data sets. This parameter 'c', might also be used as a customary attribute of the particle production in high energy nuclear collisions [9]. Bershadskii [10] provided Thermodynamics in Multiparticle Production in Relativistic Heavy-Ion Collisions a thermodynamic explanation of the concluded outcome with reference to CSH.…”

Section: Introductionmentioning

confidence: 99%

Constant Specific Heat Approximation in Multifractal Thermodynamics in Multiparticle Production in Relativistic Heavy-Ion Collisions

Kamal¹,

Khan²

2022

AJMP

0

View full text Add to dashboard Cite

The study of specific heat is motivated by the fact that a sudden change in the value of specific heat might be interpreted as a signal of a phase transition. It is also an established fact that multifractal analysis has been proved to be highly effective in characterizing fluctuations which is considered to be important tool for understanding the mechanism of quark-gluon plasma (QGP) in high energy nucleus-nucleus collisions. The Present research work provides some fascinating investigations on multifractal specific heat, c using the concept of entropy, f q which is found as a potential procedure in the study of multifractal specific heat along with the earlier known approaches. The investigations are done for the produced shower particles in nuclear emulsion detector for 28 Si-nucleus interactions at 14.5 A GeV/c in the framework of generalized dimension. An attempt is also made to discuss certain universal properties of multifractal specific heat and entropy. We have computed c, by applying the methodology of modified and Takagi moments (T q ). Experimental results are compared with the predictions of LUND model FRITIOF. Moreover, the constant-specific heat method, which is based on the concept of entropy and is commonly accepted in conventional thermodynamics, is demonstrated to be suitable in multifractal thermodynamics also. The values of 'c' calculated from these methods are compared with constant specific heat approximations (CSHs) obtained using multifractal entropy (f q ). It is found that the values of 'c', estimated using Takagi approach are consistent with those of Bershadskii's work as compared to those calculated using (G a m ) moments and multifractal entropy, f q . This is obtained for both experimental and for the FRITIOF generated data for the three types of interactions namely, CNO, emulsion and AgBr. The findings of this paper reveal useful information regarding the choice of method used and our results are consistent with CSH approximation for both experimental and simulated data and also in conjunction with recent studies on multifractal specific heat.

show abstract

“…ebe fluctuations in hadronic and heavy-ion collisions have been investigated at widely different energies using several different approaches, for example, normalized factorial moments [12][13][14][15], multifractals [16,17], k-order rapidity spacing [18][19][20], erraticity [21][22][23], and intensive and strongly intensive quantities (defined in terms of multiplicity, transverse momentum, p T , etc.) [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Event-by-Event Particle Ratio Fluctuations at LHC Energies

Khan

¹

,

Ali

²

,

Chandra

³

et al. 2021

Advances in High Energy Physics

Self Cite

2

0

View full text Add to dashboard Cite

A Monte Carlo study of identified particle ratio fluctuations at LHC energies is carried out in the framework of HIJING model using the fluctuation variable ν dyn . The simulated events for Pb-Pb collisions at s N N = 2.76 and 5.02 TeV and Xe-Xe collisions at s N N = 5.44 TeV are analyzed. From this study, it is observed that the values of π , K , p , K , and π , p follow the similar trends of energy dependence as observed in the most central collision data by NA49, STAR, and ALICE experiments. It is also observed that ν dyn for all the three combinations of particles for semicentral and central collisions, the model predicted values of ν dyn A , B for Pb-Pb collisions at s N N = 2.76 TeV agree fairly well with those observed in the ALICE experiment. For peripheral collisions, however, the model predicted values of ν dyn π , K are somewhat smaller, whereas for p , K and π , p it predicts larger values as compared to the corresponding experimental values. The possible reasons for the observed differences are discussed. The ν dyn values scaled with charged particle density when plotted against N part exhibit a flat behaviour, as expected from the independent particle emission sources. For p , K and π , p combinations, a departure from the flat trend is, however, observed in central collisions in the case of low p T window when the effect of jet quenching or resonances is considered. Furthermore, the study of ν dyn A , B dependence on particle density for various collision systems (including proton-proton collisions) suggests that at LHC energies ν dyn values for a given particle pair are simply a function of charged particle density, irrespective of system size, beam energy, and collision centrality.

show abstract

Multifractal characteristics of multiparticle production in heavy-ion collisions at SPS energies

Cited by 6 publications

References 57 publications

Event-by-event fluctuations clusterization and entropy production in AA collisions at AGS and SPS energies

Event-by-event fluctuations clusterization and entropy production in AA collisions at AGS and SPS energies

Constant Specific Heat Approximation in Multifractal Thermodynamics in Multiparticle Production in Relativistic Heavy-Ion Collisions

Event-by-Event Particle Ratio Fluctuations at LHC Energies

Contact Info

Product

Resources

About