Systematic investigation of partonic collectivity through centrality dependence of elliptic flow of multi-strange hadrons in Au + Au collisions at sNN=200 GeV in STAR

We present the measurement of centrality dependence of multi-strange hadrons (Ω,Ξ and ϕ) elliptic flow (v2) at mid-rapidity in Au + Au collision at sNN=200 GeV.We investigate number-of-constituent quark (NCQ) scaling of identified hadrons v2 for different collision centralities. Maximum deviation from ideal NCQ scaling is observed at the level of 10% for centrality 30-80% at (mT−m0)/nq>0.6 GeV/c2. This may indicate smaller contribution to the collectivity from the partonic phase in the peripheral collisions. We also observe that the mass ordering of v2 break down between proton and ϕ-meson for pT<1 GeV/c. This could be due to the effect of later stage hadronic interactions on v2.