Particle-Type Dependence of Azimuthal Anisotropy and Nuclear Modification of Particle Production in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">A</mml:mi><mml:mi mathvariant="normal">u</mml:mi><mml:mo>+</mml:mo><mml:mi mathvariant="normal">A</mml:mi><mml:mi mathvariant="normal">u</mml:mi></mml:math>Collisions at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:msub><mml:mi>s</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>N</mml:mi></mml:mrow></mml:msub></mml:msqrt><mml:mo>=</mml:mo><mml:mn>200</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi mathvariant="normal">G</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi mathvariant="normal">V</mml:mi></mml:math>
Аннотация
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.
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