203 articles – 1878 Notices  [english version]
 HAL : in2p3-00718709, version 1
 arXiv : 1111.5637
 Physical Review C 86 (2011) 014904
 Energy and system-size dependence of two- and four-particle $v_2$ measurements in heavy-ion collisions at RHIC and their implications on flow fluctuations and nonflow
 STAR Collaboration(s)
 (2011)
 We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\{2\}$ and $v_2\{4\}$) for Au+Au and Cu+Cu collisions at center of mass energies $\sqrt{s_{_{\mathrm{NN}}}} = 62.4$ and 200 GeV. The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ is related to $v_{2}$ fluctuations ($\sigma_{v_2}$) and nonflow $(\delta_{2})$. We present an upper limit to $\sigma_{v_2}/v_{2}$. Following the assumption that eccentricity fluctuations $\sigma_{\epsilon}$ dominate $v_2$ fluctuations $\frac{\sigma_{v_2}}{v_2} \approx \frac{\sigma_{\epsilon}}{\epsilon}$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\{2\}$ and $v_2\{4\}$. We also present results on the ratio of $v_2$ to eccentricity.
 Thème(s) : Physique/Physique des Hautes Energies - ExpériencePhysique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1111.5637
 in2p3-00718709, version 1 http://hal.in2p3.fr/in2p3-00718709 oai:hal.in2p3.fr:in2p3-00718709 Contributeur : Sylvie Florès <> Soumis le : Mercredi 18 Juillet 2012, 08:30:10 Dernière modification le : Mercredi 18 Juillet 2012, 08:39:26