scholarly journals Multifractal Analysis of Charged Particle Multiplicity Distribution in the Framework of Renyi Entropy

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Swarnapratim Bhattacharyya ◽  
Maria Haiduc ◽  
Alina Tania Neagu ◽  
Elena Firu

A study of multifractality and multifractal specific heat has been carried out for the produced shower particles in nuclear emulsion detector for 16O-AgBr, 28Si-AgBr, and 32S-AgBr interactions at 4.5AGeV/c in the framework of Renyi entropy. Experimental results have been compared with the prediction of Ultra-Relativistic Quantum Molecular Dynamics (UrQMD) model. Our analysis reveals the presence of multifractality in the multiparticle production process in high energy nucleus-nucleus interactions. Degree of multifractality is found to be higher for the experimental data and it increases with the increase of projectile mass. The investigation of quark-hadron phase transition in the multiparticle production in 16O-AgBr, 28Si-AgBr, and 32S-AgBr interactions at 4.5 AGeV/c in the framework of Ginzburg-Landau theory from the concept of multifractality has also been presented. Evidence of constant multifractal specific heat has been obtained for both experimental and UrQMD simulated data.

2017 ◽  
Vol 95 (8) ◽  
pp. 715-719 ◽  
Author(s):  
Swarnapratim Bhattacharyya ◽  
Maria Haiduc ◽  
Alina Tania Neagu ◽  
Elena Firu

A study of Renyi entropy of shower particles has been carried out using 16O, 28Si, and 32S projectiles in interaction with AgBr and CNO target present in nuclear emulsion at an incident momentum of 4.5 AGeV/c. The analysis reveals interesting experimental observations for both groups of targets. A comparison of the experimental results with the results obtained from analyzing the event sample generated by the UrQMD code is also presented. Renyi entropy values increase with the increase of projectile mass. This increase is weaker in case of CNO target. The calculated values of second-order Renyi entropy H2 are shown to vary linearly with the logarithm of average particle multiplicity ln⟨n⟩ for both targets. The dependence of Renyi entropy on the logarithm of average particle multiplicity ln⟨n⟩ indicates the presence of long-range correlation in high-energy nucleus–nucleus interactions. The variation is found to be stronger in the case of experimental events in comparison to the UrQMD simulated events indicating stronger long-range correlation for the experimental data.


2020 ◽  
Vol 35 (36) ◽  
pp. 2050302
Author(s):  
Amr Radi

With many applications in high-energy physics, Deep Learning or Deep Neural Network (DNN) has become noticeable and practical in recent years. In this article, a new technique is presented for modeling the charged particles multiplicity distribution [Formula: see text] of Proton-Proton [Formula: see text] collisions using an efficient DNN model. The charged particles multiplicity n, the total center of mass energy [Formula: see text], and the pseudorapidity [Formula: see text] used as input in DNN model and the desired output is [Formula: see text]. DNN was trained to build a function, which studies the relationship between [Formula: see text]. The DNN model showed a high degree of consistency in matching the data distributions. The DNN model is used to predict with [Formula: see text] not included in the training set. The expected [Formula: see text] had effectively merged the experimental data and the values expected indicate a strong agreement with Large Hadron Collider (LHC) for ATLAS measurement at [Formula: see text], 7 and 8 TeV.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Provash Mali ◽  
Soumya Sarkar ◽  
Amitabha Mukhopadhyay ◽  
Gurmukh Singh

A continuous wavelet analysis is performed for pattern recognition of charged particle emission data in28Si-Ag/Br interaction at 14.5A GeV and in32S-Ag/Br interaction at 200A GeV. Making use of the event-wise local maxima present in the scalograms, we try to identify the collective behavior in multiparticle production, if there is any. For the first time, the wavelet results are compared with a model prediction based on the ultrarelativistic quantum molecular dynamics (UrQMD), where we adopt a charge reassignment algorithm to modify the UrQMD events to mimic the Bose-Einstein type of correlation among identical mesons—a feature known to be the most dominating factor responsible for local cluster formation. Statistically significant deviations between the experiment and the simulation are interpreted in terms of nontrivial dynamics of multiparticle production.


2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Sandeep Chatterjee ◽  
Sabita Das ◽  
Lokesh Kumar ◽  
D. Mishra ◽  
Bedangadas Mohanty ◽  
...  

We review the chemical and kinetic freeze-out conditions in high energy heavy-ion collisions for AGS, SPS, RHIC, and LHC energies. Chemical freeze-out parameters are obtained using produced particle yields in central collisions while the corresponding kinetic freeze-out parameters are obtained using transverse momentum distributions of produced particles. For chemical freeze-out, different freeze-out scenarios are discussed such as single and double/flavor dependent freeze-out surfaces. Kinetic freeze-out parameters are obtained by doing hydrodynamic inspired blast wave fit to the transverse momentum distributions. The beam energy and centrality dependence of transverse energy per charged particle multiplicity are studied to address the constant energy per particle freeze-out criteria in heavy-ion collisions.


Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  

AbstractThe study of (anti-)deuteron production in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper the production of $$\text {(anti-)deuterons}$$ (anti-)deuterons is studied as a function of the charged particle multiplicity in inelastic pp collisions at $$\sqrt{s}=13$$ s = 13 TeV using the ALICE experiment. Thanks to the large number of accumulated minimum bias events, it has been possible to measure (anti-)deuteron production in pp collisions up to the same charged particle multiplicity ($${\mathrm {d} N_{ch}/\mathrm {d} \eta } \sim 26$$ d N ch / d η ∼ 26 ) as measured in p–Pb collisions at similar centre-of-mass energies. Within the uncertainties, the deuteron yield in pp collisions resembles the one in p–Pb interactions, suggesting a common formation mechanism behind the production of light nuclei in hadronic interactions. In this context the measurements are compared with the expectations of coalescence and statistical hadronisation models (SHM).


2018 ◽  
Vol 171 ◽  
pp. 18003 ◽  
Author(s):  
Grigory Feofilov ◽  
Vladimir Kovalenko ◽  
Andrei Puchkov

The multiplicity dependence of heavy flavour production in pp-collisions at LHC energies is studied in the framework of the multi-pomeron exchange model. The model is introducing the string-string interaction collectivity effects in pp collisions, which modifies multiplicity and transverse momenta, leading to the non-trivial mean pt vs. multiplicity (〈pt〉Nch − Nch). correlation. The string collectivity strength parameter is fixed by experimental data on multiplicity and transverse momentum correlation in a wide energy range (from ISR to LHC). The particles discrimination is implemented according to Schwinger mechanism taking into account the strong decays of hadron resonances. We demonstrate, that the faster-than-linear growth of the open charm production with the event charged particle multiplicity, observed in experimental pp high energy collisions, can be explained by the modification of the string tension due to the increasing overlap and interaction of quark-gluon strings. The model is extended for p-A interactions and the calculations for p-Pb collisions are performed.


1994 ◽  
Vol 09 (36) ◽  
pp. 3359-3366 ◽  
Author(s):  
S. CHATURVEDI ◽  
V. GUPTA ◽  
S.K. SONI

Various probability distributions which have been proposed to explain the charged particle multiplicity distributions in high energy collisions are shown to arise from the evolution equation of a pure birth process subject to appropriate initial conditions. For example, both the negative binomial distribution (NBD) as well as the partially coherent laser distribution (PCLD) can be obtained in this way. New interrelations between some of these probability distributions are also brought out.


2017 ◽  
Vol 32 (08) ◽  
pp. 1750024 ◽  
Author(s):  
P. Mali ◽  
A. Mukhopadhyay ◽  
S. K. Manna ◽  
P. K. Haldar ◽  
G. Singh

Horizontal visibility graphs (HVGs) and the sandbox (SB) algorithm usually applied for multifractal characterization of complex network systems that are converted from time series measurements, are used to characterize the fluctuations in pseudorapidity densities of singly charged particles produced in high-energy nucleus–nucleus collisions. Besides obtaining the degree distribution associated with event-wise pseudorapidity distributions, the common set of observables, typical of any multifractality measurement, are studied in [Formula: see text]O-Ag/Br and [Formula: see text]S-Ag/Br interactions, each at an incident laboratory energy of 200 GeV/nucleon. For a better understanding, we systematically compare the experiment with a Monte Carlo model simulation based on the Ultra-relativistic Quantum Molecular Dynamics (UrQMD). Our results suggest that the HVG-SB technique is an efficient tool that can characterize multifractality in multiparticle emission data, and in some cases, it is even superior to other methods more commonly used in this regard.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ramni Gupta ◽  
Salman Khurshid Malik

Charged particle multiplicity fluctuations in Pb-Pb collisions are studied for the central events generated using EPOS3 (hydro and hydro+cascade) at sNN=2.76 TeV. Intermittency analysis is performed in the midrapidity region in two-dimensional (η, ϕ) phase space within the narrow transverse momentum (pT) bins in the low pT region (pT≤1.0 GeV/c). Power-law scaling of the normalized factorial moments with the number of bins is not observed to be significant in any of the pT bins. Scaling exponent ν, deduced for a few pT bins, is greater than that of the value 1.304, predicted for the second-order phase transition by the Ginzburg-Landau theory. The link in the notions of fractality is also studied. Generalized fractal dimensions, Dq, are observed to decrease with the order of the moment q suggesting the multifractal nature of the particle generation in EPOS3.


Sign in / Sign up

Export Citation Format

Share Document