Particle-Type Dependence of Azimuthal Anisotropy and Nuclear Modification of Particle Production inAu+AuCollisions atsNN=200 GeV

We present STAR measurements of the azimuthal anisotropy parameter ${v}_{2}$ and the binary-collision scaled centrality ratio ${R}_{\mathrm{C}\mathrm{P}}$ for kaons and lambdas ($\ensuremath{\Lambda}+\overline{\ensuremath{\Lambda}}$) at midrapidity in $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. In combination, the ${v}_{2}$ and ${R}_{\mathrm{C}\mathrm{P}}$ particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish ${p}_{T}\ensuremath{\approx}5\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ as the value where the centrality dependent baryon enhancement ends. The ${K}_{S}^{0}$ and $\ensuremath{\Lambda}+\overline{\ensuremath{\Lambda}}$ ${v}_{2}$ values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

Particle-Type Dependence of Azimuthal Anisotropy and Nuclear Modification of Particle Production inAu+AuCollisions atsNN=200 GeV | Litlas