Identified Hadrons and Jet Chemistry for p+p and Au+Au Collisions at RHIC

Abstract

The study of hadron spectra at high $p_T$ in p+p collisions provides a good test of perturbative quantum chromo-dynamic calculations (pQCD) and baseline for measurements of nuclear modification factors in Au+Au collisions. Using events triggered by the Barrel Electro-Magnetic Calorimeter, identified charged hadron transverse momentum ($p_T$) spectra are measured up to 15 GeV/$c$ at mid-rapidity ($\mid y\mid$ $<$ 0.5) and neutral kaon $p_T$ spectra up to 12 GeV/$c$ in p + p collisions at $\sqrt{s_{NN}}$ = 200 GeV. The particle ratios of $p/{\pi }^{+}$, $\bar{p}/{\pi }^{-}$ and $K^{\pm ,0}$ / ${\pi }^{\pm }$ in p + p collisions are shown and compared with next-to-leading order pQCD calculations. In central Au+Au collisions, we report nuclear modification factors ($R_{AA}$) for pion, kaon, proton and $\rho$ and discuss several model calculations: color-charge dependence of jet quenching and jet conversion. Finally, centrality dependence of $R_{AA}$ at high $p_T$ ($>$ 5.5 GeV/c) for kaon are compared with that of pion in Au + Au collisions at 200 GeV.

6 pages, 4 figures, SQM 2009 contribution

References in corpus (6)

• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• Measurements of Strange Particle Production in $p+p$ Collisions at $\sqrt{s}$= 200 GeV
• Probing Nuclear Matter with Jet Conversions
• Measurements of neutral and charged kaon production at high pT up to 15 GeV/c at STAR
• Identified hadron production at high transverse momenta in p+p collisions at sqrt(NN) = 200 GeV in STAR
• Production at High $p_T$ in Central Au+Au and $p+p$ collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV in STAR

Cited by in corpus (4)

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• A Very High Momentum Particle Identification Detector
• Production and energy loss of strange and heavy quarks
• Strangeness production in high-multiplicity events