HAL : in2p3-00285369, version 1
 arXiv : 0805.1521
 Physical Review C 78 (2008) 044902
 Charged hadron multiplicity fluctuations in Au+Au and Cu+Cu collisions from sqrt(s_NN) = 22.5 to 200 GeV
 PHENIX Collaboration(s)
 (2008)
 A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for non-dynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. An analysis of Negative Binomial Distribution fits to the multiplicity distributions demonstrates that the heavy ion data exhibit weak clustering properties.
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0805.1521
 in2p3-00285369, version 1 http://hal.in2p3.fr/in2p3-00285369 oai:hal.in2p3.fr:in2p3-00285369 Contributeur : Dominique Girod <> Soumis le : Jeudi 5 Juin 2008, 11:37:06 Dernière modification le : Jeudi 13 Novembre 2008, 11:46:06