Multifractal detrended fluctuation analysis of particle density fluctuations in high-energy nuclear collisions

The detrended fluctuation analysis (DFA) and the multifractal DFA (MF-DFA) techniques are employed to characterize the pseudorapidity (η) distribution of charged mesons produced in 28Si+Ag/Br interaction at 14.5 GeV/nucleon and 32S+Ag/Br interaction at 200 GeV/nucleon. Various multifractal parameters are calculated and compared with a Monte-Carlo simulation based on the ultra-relativistic quantum molecular dynamics (UrQMD) model. The results of this analysis show that the single particle distributions in both experiments and in their respective UrQMD simulations are multifractal in nature. The differences between the experiment and corresponding simulation however, are not always very significant. But the present results are significantly different from those obtained by using other conventional methods of multifractal analysis. The observations also indicate that the detrended multifractal analysis might be an efficient tool for characterizing the multiparticle emission data, but the method requires some improvement so that it can differentiate between the non-statistical signal and the statistical noise.