Measurements of second-harmonic Fourier coefficients from azimuthal anisotropies in p plus p, p plus Au, d + Au, and 3He+Au collisions at SQUARE ROOTsNN=200 GeV
Abstract
Recently, the PHENIX Collaboration has published second-and third-harmonic Fourier coefficients v2 and v3 for midrapidity (|eta| < 0.35) charged hadrons in 0%-5% central p + Au, d + Au, and 3He +Au collisions at N/sNN = 200 GeV, utilizing three sets of two-particle correlations for two detector combinations with different pseudorapidity acceptance [Acharya et al., Phys. Rev.
C 105, 024901 (2022)]. This paper extends these measurements of v2 to all centralities in p + Au, d + Au, and 3He +Au collisions, as well as p + p collisions, as a function of transverse momentum (pT) and event multiplicity.
The kinematic dependence of v2 is quantified as the ratio R of v2 between the two detector combinations as a function of event multiplicity for 0.5 < pT < 1 and 2 < pT < 2.5 GeV/c. A multiphase-transport (AMPT) model can reproduce the observed v2 in most-central to midcentral d + Au and 3He +Au collisions.
However, the AMPT model systematically overestimates the measurements in p + p, p + Au, and peripheral d + Au and 3He +Au collisions, indicating a higher nonflow contribution in the AMPT model than in the experimental data. The AMPT model fails to describe the observed R for 0.5 < pT < 1 GeV/c, but there is qualitative agreement with the measurements for 2 < pT < 2.5 GeV/c.