Elliptic flow for φ-mesons in Cu+Au and U+U collisions

An important goal of current ultra-relativistic heavy ion research is the investigation of the quark-gluon plasma (QGP). Measurements of elliptic flow lend insight on reaction dynamics and are important for defining parameters of viscous hydrodynamic, which can describe QGP behavior. In this paper elliptic flow for φ-mesons in Cu+Au collisions at s N N = 200 GeV and in U+U collisions at s N N = 193 GeV GeV is studied as a function of kinetic properties and centrality. The obtained results are compared to hydrodynamic model predictions. New FVTX detector and combinations of different approaches of flow measurements provide a possibility to measure the elliptic flow for the φ -mesons for the first time as a function of centrality at PHENIX. The elliptic flow for φ -mesons in Cu+Au and U+U collisions as function of transverse kinetic energy per one quark follows the trend for other hadrons with respect to the number of quarks in hadrons, regardless of centrality. This result along with agreement of obtained data to hydrodynamic model iEBE-VISHNU predictions suggests that QGP can be described with viscous hydrodynamic with specific viscosity η/s = 1/(4π).