Event-by-event fluctuations in p+p and central A+A collisions within relativistic transport models

Abstract

Event-by-event multiplicity fluctuations in nucleus-nucleus collisions are studied within the relativistic transport models: EPOS, PHSD, and UrQMD. As measures of particle number fluctuations we consider the scaled variances $\omega [X]$ for positive, negative, and all charged hadrons, and the strongly intensive quantities $\Delta [K^{+},{\pi }^{+}],$ $\Sigma [K^{+},{\pi }^{+}]$ for $K^{+}$ and ${\pi }^{+}$ yields. At the SPS energy range the fluctuation measures are calculated for proton-proton, Ar+Sc, and Pb+Pb collisions. Comparison with recent NA61/SHINE and older NA49 measurements of the multiplicity fluctuations is done. A validity of the model of independent sources, a role of the experimental acceptance, and the centrality selection procedure are studied.Event-by-event multiplicity fluctuations in nucleus-nucleus collisions are studied within the relativistic transport models: EPOS, PHSD, and UrQMD. As measures of particle number fluctuations we consider the scaled variances $\omega [X]$ for positive, negative, and all charged hadrons, and the strongly intensive quantities $\Delta [K^{+},{\pi }^{+}],$ $\Sigma [K^{+},{\pi }^{+}]$ for $K^{+}$ and ${\pi }^{+}$ yields. At the SPS energy range the fluctuation measures are calculated for proton-proton, Ar+Sc, and Pb+Pb collisions. Comparison with recent NA61/SHINE and older NA49 measurements of the multiplicity fluctuations is done. A validity of the model of independent sources, a role of the experimental acceptance, and the centrality selection procedure are studied.

Comments: 9 pages, 10 figures, Accepted for publication in Journal of Physics G