Neutral Pion Elliptic Flow in p + Au Collisions at 200 GeV

One of the priority goals of the PHENIX experiment is the study of collective effects in small collision systems, such as proton-nucleus interactions. The results of measurements of the elliptic flow ( $${{v}_{2}}$$ ) of neutral pions in p + Au collisions at the energy $$\\sqrt {{{s}_{{NN~}}}} $$ = 200 GeV are presented. The dependence of $${{v}_{2}}$$ on transverse momentum $$({{p}_{{\\text{T}}}}$$ ) of particles and on the collision centrality has been investigated. A comparison is presented between the measured $${{\\pi }^{0}}$$ $${{v}_{2}}$$ values in p + Au collisions at the energy $$\\sqrt {{{s}_{{NN~}}}} $$ = 200 GeV and previously measured $${{v}_{2}}$$ values for various particles species at the PHENIX experiment. The results obtained are important for understanding the mechanisms of collective behavior in small collision systems and for testing the applicability of hydrodynamic models to proton-nucleus collisions.