Physics and Astronomy
Journal or Book Title
Physical Review C
Measurements of the anisotropy parameter v(2) of identified hadrons (pions, kaons, and protons) as a function of centrality, transverse momentum p(T), and transverse kinetic energy KET at midrapidity (vertical bar eta vertical bar < 0.35) in Au + Au collisions at root s(N N) = 200 GeV are presented. Pions and protons are identified up to p(T) = 6 GeV/c, and kaons up to p(T) = 4 GeV/c, by combining information from time-of-flight and aerogel Cerenkov detectors in the PHENIX Experiment. The scaling of v(2) with the number of valence quarks (n(q)) 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/n(q) in noncentral Au + Au collisions (20-60%), but this scaling remains valid in central collisions (0-10%).
American Physical Society
Adare, Andrew; Hill, John C.; Kempel, Todd; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Pei, H.; Rosati, Marzia; Semenov, Alexey Yu.; Vale, Carla; Wei, Feng; et al.; and PHENIX Collaboration, "Deviation from quark number scaling of the anisotropy parameter v(2) of pions, kaons, and protons in Au+Au collisions at root s(NN)=200 GeV" (2012). Physics and Astronomy Publications. 258.