Physics and Astronomy
Journal or Book Title
Physical Review C
We present measurements of the transverse-momentum dependence of elliptic flow upsilon(2) for identified pions and (anti)protons at midrapidity (vertical bar eta vertical bar < 0.35), in 0%-5% central p + Au and He-3 + Au collisions at ,root s(NN) = 200 GeV. When taken together with previously published measurements in d + Au collisions at root s(NN) = 200 GeV, the results cover a broad range of small-collision-system multiplicities and intrinsic initial geometries. We observe a clear mass-dependent splitting of upsilon(2) (p(T)) in d + Au and He-3 + Au collisions, just as in large nucleus-nucleus (A + A) collisions, and a smaller splitting in p + Au collisions. Both hydrodynamic and transport model calculations successfully describe the data at low p(T) (<1.5 GeV/c), but fail to describe various features at higher p(T). In all systems, the upsilon(2) values follow an approximate quark-number scaling as a function of the hadron transverse kinetic energy per constituent quark (KET/n(q)), which was also seen previously in A + A collisions.
American Physical Society
Adare, A.; Apadula, Nicole J.; Campbell, Sarah C.; Hill, John C.; Hotvedt, Nels J.; Lajoie, John G.; Lebedev, Alexandre; Lee, S. H.; Ogilvie, Craig; Patel, Milap R.; Perry, Joshua; Rinn, Timothy T.; Rosati, Marzia; Runchey, Jonathan C.; Sen, Abhisek; Shimomura, M.; Timilsina, Arbin; et al.; and PHENIX Collaboration, "Measurements of mass-dependent azimuthal anisotropy in central p + Au, d + Au, and 3He + Au collisions at √sNN = 200 GeV" (2018). Physics and Astronomy Publications. 493.