Some observations on Levy stability and intermittency in nucleus-nucleus interactions at SPS energies

The power law relation between higher order and second order scaled factorial moments is studied in one dimensional pseudo-rapidity phase (eta) space in the interactions of S-32 beam with CNO, AgBr and Emulsion at incident energy of 200 AGeV. Observation for such a power law may indicate a self similar cascade mechanism in multiparticle production process. The values of slope, beta(q) are found to be independent of target size. The value of the scaling exponent upsilon = 1.412 obtained is higher than the critical value upsilon = 1.304, indicating that no second order phase transition exists in our data. The ratio of anomalous fractal dimensions, d(q)/d(2) is found to increase with increase in the order of moments, q. The dependence of d(q)/d(2) on q indicates a multifractal structure and the presence of self-similar cascading mechanism in our data. The d(q)/d(2) values are well described by the Levy-stable distribution with Levy index mu = 1.562 which is consistent with and lies within the Levy stable region (0 <= mu <= 2). The multifractal spectrum is concave downward with a maximum at q = 0. The decrease in D-q with increasing q shows that there is a self affine multifractal behaviour in multiparticle production in our data. (C) 2017 The Physical Society of the Republic of China (Taiwan). Published by Elsevier B.V. All rights reserved.