Target excitation dependence of degree of multifractality and critical exponent in ultrarelativistic nuclear collision

Abstract

The target excitation dependence of the degree of multifractality and critical exponent of pions produced for the 16O-AgBr interaction at 60 AGeV has been investigated. To study target excitation dependence, the data for the produced pions were distributed into three sets, depending on the number of grey tracks (ng). The different sets correspond to the different degrees of target excitation. The probability G-moments were used for the analysis in pseudorapidity space. The analysis reveals that the produced particle density distribution possesses multifractal structure for all degrees of target excitation (0 ≤ ng ≤ 3, 4 ≤ ng ≤ 7, and ng ≥ 8). The distribution Levy index and the phase transition critical exponent are calculated. The study indicates the non-thermal phase transition, but it does not show evidence for the second-order phase transition.