Measurements of the anisotropy parameter v2 of identified hadrons (pions, kaons, and protons) as a function of centrality, transverse momentum pT , and transverse kinetic energy KET at midrapidity (|_| < 0.35) in Au+Au collisions at psNN = 200 GeV are presented. Pions and protons are identified up to pT = 6 GeV/c, and kaons up to pT = 4 GeV/c, by combining information from time-of-flight and aerogel ˇ Cerenkov detectors in the PHENIX Experiment. The scaling of v2 with the number of valence quarks (nq) has been studied in different centrality bins as a function of transverse momentum and transverse kinetic energy. A deviation from previously observed quark-number scaling is observed at large values of KET /nq in noncentral Au+Au collisions (20–60%), but this scaling remains valid in central collisions (0–10%).
Fields, Douglas E.. "Deviation from quark-number scaling of the anisotropy parameter v_2 of pions, kaons, and protons in Au+ Au collisions at sqrt (s_NN)= 200 GeV." (2012). http://digitalrepository.unm.edu/phyc_fsp/8