Strange quark collectivity of $\phi$ meson at RHIC
  Based on A Multi-Phase Transport model, the elliptic flow $v_{2}$ of $\phi$ mesons which is reconstructed from $K^{+}K^{-}$ at the Relativistic Heavy Ion Collider (RHIC) energy has been studied. The results show that reconstructed $v_{2}$ of $\phi$ meson can keep the earlier information before $\phi$ decays and it seems to obey the number of constituent quark scaling as other mesons and baryons. This result indicates that the $\phi$ $v_2$ mostly reflects the parton level collectivity developed during the early stage of the collisions and the strange and light up/down quarks have similar collectivity properties before the hadronization. 
J. H. Chen, Y. G. Ma*, G. L. Ma, H. Z. Huang, X. Z. Cai, Z. J. He, J.   L. Long, W. Q. Shen, J. X. Zuo