Systematic study of azimuthal anisotropy in Cu + Cu and Au + Au collisions at = 62.4 and 200 GeV

=62.4および200GeVでの銅-銅衝突および金-金衝突における方位角異方性のシステマティックな研究

Adare, A.*; 今井 憲一; 佐藤 進  ; 谷田 聖   ; PHENIX Collaboration*; 他420名*

Adare, A.*; Imai, Kenichi; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 420 of others*

We have studied the dependence of azimuthal anisotropy for inclusive and identified charged hadrons in Au + Au and Cu + Cu collisions on collision energy, species, and centrality. The values of as a function of transverse momentum and centrality in Au+Au collisions at = 200 and 62.4 GeV are the same within uncertainties. However, in Cu + Cu collisions we observe a decrease in values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au + Au and Cu + Cu collisions we find that depends both on eccentricity and the number of participants, . We observe that divided by eccentricity () monotonically increases with and scales as . The Cu + Cu data at 62.4 GeV falls below the other scaled data. For identified hadrons, divided by the number of constituent quarks is independent of hadron species as a function of transverse kinetic energy between GeV. Combining all of the above scaling and normalizations, we observe a near-universal scaling, with the exception of the Cu + Cu data at 62.4 GeV, of vs for all measured particles.