Study of Anomalous Fractal Dimensions and Scaling Exponent in Ginzburg--Landau Phase Transition in 14.5 $A$\,GeV/$c$ $^{28}$Si--AgBr Interactions

2015 ◽  
Vol 46 (8) ◽  
pp. 1549 ◽  
Author(s):  
A. Kamal ◽  
N. Ahmad ◽  
M.M. Khan
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.


1999 ◽  
Vol 14 (10) ◽  
pp. 1551-1559 ◽  
Author(s):  
ZHEN CAO ◽  
RUDOLPH C. HWA

The evolution of cooperative behavior is studied in the deterministic version of the Prisoners' Dilemma on a two-dimensional lattice. The payoff parameter is set at the critical region 1.8<b<2.0, where clusters of cooperators are formed in all spatial sizes. Using the factorial moments developed in particle and nuclear physics for the study of phase transition, the distribution of cooperators is studied as a function of the bin size covering varying numbers of lattice cells. From the scaling behavior of the moments a scaling exponent is determined and is found to lie in the range where phase transitions are known to take place in physical systems. It is therefore inferred that when the payoff parameter is increased through the critical region the biological system of cooperators undergoes a phase transition to defectors. The universality of the critical behavior is thus extended to include also this particular model of evolution dynamics.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Rohni Sharma ◽  
Ramni Gupta

From the events generated from the MC code of a multiphase transport (AMPT) model with string melting, the properties of multiplicity fluctuations of charged particles in Pb–Pb collisions at sNN = 2.76 TeV are studied. Normalized factorial moments, Fq, of spatial distributions of the particles have been determined in the framework of intermittency. Those moments are found in some kinematic regions to exhibit scaling behavior at small bin sizes, but not in most regions. However, in relating Fq to F2 scaling behavior is found in nearly all regions. The corresponding scaling exponents, ν, determined in the low transverse momentum (pT) region ≤ 1.0 GeV/c are observed to be independent of the pT bin position and width. The value of ν is found to be larger than 1.304, which is the value that characterizes the Ginzburg-Landau type second-order phase transition. Thus there is no known signature for phase transition in the AMPT model. This study demonstrates that, for the system under investigation, the method of analysis is effective in extracting features that are relevant to the question of whether the dynamical processes leading phase transition are there or not.


2012 ◽  
Vol 45 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Dipak Ghosh ◽  
Argha Deb ◽  
Ruma Saha ◽  
Rupa Das ◽  
Nurul Alam

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