Flavor ordering of elliptic flows at high transverse momentum

Abstract

Based on the quark coalescence model for the parton-to-hadron phase transition in ultra-relativistic heavy ion collisions, we relate the elliptic flow ($v_2$) of high $\pt$ hadrons to that of high $\pt$ quarks. For high $\pt$ hadrons produced from an isospin symmetric and quark-antiquark symmetric partonic matter, magnitudes of their elliptic flows follow a flavor ordering as $(v_{2,π}=v_{2,N}) > (v_{2,Λ}=v_{2,Σ}) > v_{2,K} > v_{2,Ξ} > (v_{2,ϕ}=v_{2,Ω})$ if strange quarks have a smaller elliptic flow than light quarks. The elliptic flows of high $\pt$ hadrons further follow a simple quark counting rule if strange quarks and light quarks have same high $\pt$ spectrum and coalescence probability.