System Size and Collision Energy Dependence of \(v_2\) for Identified Charged Hadrons at RHIC-PHENIX

• Published in: arXiv.org 2009-10
• Main Authors: Shimomura, Maya, the PHENIX Collaboration
• Format: Article
• Language: English
• Subjects: Anisotropy; Dependence; Eccentricity; Hadrons; Quarks; Scaling; Transverse momentum
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0908.0052

The transverse momentum (\(p_{\rm T}\)) and centrality dependence of the azimuthal anisotropy (\(v_{2}\)) are measured for charged hadrons in different energies and collision species by the PHENIX experiment at RHIC. We find that \(v_{2}\) divided by the participant eccentricity of the initial geometry proportionally increases with the number of participants to the 1/3 power except at small \(N_{\rm part}\) in Cu+Cu at \(\sqrt{s_{\rm NN}}\) = 62.4 GeV. Taking the eccentricity and quark number scaling into account, there is a universal scaling for \(v_{2}\) with different energies and collision sizes. The results indicate that \(v_{2}\) is determined by more than just the geometrical eccentricity. It also depends on the size of collision. We also report that both the behaviors of \(v_{2}\) and \(p_{\rm T}\) distributions can be understood from the thermal nature of produced particles based on hydro-dynamical behavior.