Investigation of dynamical pseudorapidity fluctuations using strongly intensive quantities on event-by-event basis in nucleus–nucleus interactions at CERN SPS energies

Abstract

The event-by-event pseudorapidity and multiplicity fluctuations have been investigated for relativistic charged particles produced in [Formula: see text]O–AgBr at 60[Formula: see text]A[Formula: see text]GeV/c and 200[Formula: see text]A[Formula: see text]GeV/c, and [Formula: see text]S–AgBr at 200[Formula: see text]A[Formula: see text]GeV/c. The strongly intensive measures ([Formula: see text], [Formula: see text] and [Formula: see text]) have been studied to unravel the underlying dynamics of multiparticle production. The multiplicity and pseudorapidity dependence of these fluctuation measures has been investigated and significant deviations from the expected reference values of independent particle production model have been observed, implying the presence of genuine dynamical fluctuations and correlations in these interactions. These deviations are due to the correlated particle production and not the modifications in single-particle spectrum. The hadronic rescatterings present within the framework of a multi-phase transport (AMPT) model are found to have no significant impact on the behavior of these observables. Both default and string melting AMPT generally show the same qualitative behavior as that of the experimental data. However, the string melting AMPT exhibits slightly better quantitative agreement with the experimental results.