Measurements of the nuclear modification factor and elliptic flow of $\phi$ mesons at RHIC

Abstract

The observation of meson and baryon grouping in the $R_{CP}$ and $v_2$ measurements at intermediate $p_T$ has been interpreted as a manifestation of bulk partonic matter hadronization through multi-parton dynamics such as recombination of partons. $\phi$ mesons provide unique sensitivity to test these theoretical scenarios, since the $\phi$ has a mass heavier than the proton and close to the hyperons. The $R_{CP}$ and $v_2$ measurements of $\phi$ mesons from Run IV Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV at STAR are presented. Energy and colliding system dependence of the $\phi$ yields at mid-rapidity are discussed. The results are compared to the measurements of other hadrons. Properties of strange quarks in the bulk matter at hadron formation are discussed.