182 articles – 1721 references  [version française]
 HAL: in2p3-00630071, version 1
 arXiv: 1110.0579
 Physical Review Letters 108 (2012) 072302
 Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV
 For the STAR collaboration(s)
 (2012)
 We report transverse momentum ($p_{T} \leq15$ GeV/$c$) spectra of $\pi^{\pm}$, $K^{\pm}$, $p$, $\bar{p}$, $K_{S}^{0}$, and $\rho^{0}$ at mid-rapidity in p+p and Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. Perturbative QCD calculations are consistent with $\pi^{\pm}$ spectra in p+p collisions but do not reproduce $K$ and $p(\bar{p})$ spectra. The observed decreasing antiparticle-to-particle ratios with increasing $p_T$ provide experimental evidence for varying quark and gluon jet contributions to high-$p_T$ hadron yields. The relative hadron abundances in Au+Au at $p_{T}{}^{>}_{\sim}8$ GeV/$c$ are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
 Subject(s) : Physics/Nuclear Experiment