High-$p_T$ Hadron Spectra, Azimuthal Anisotropy and Back-to-Back Correlations in High-energy Heavy-ion Collisions

Abstract

The observed suppression of high-$p_T$ hadron spectra, finite azimuthal anisotropy, disappearance of jet-like back-to-back correlations, and their centrality dependence in $Au+Au$ collisions at RHIC are shown to be quantitatively described by jet quenching within a pQCD parton model. The difference between $h^{\pm}$ and $π^0$ suppression in intermediate $p_T$ is consistent with the observed $(K+p)/π$ enhancement which should disappear at $p_T>6$ GeV/$c$. The suppression of back-to-back correlations is shown to be directly related to the medium modification of jet fragmentation functions(FF).

Figures (4)

• Figure 1: Nuclear modification factors for hadron spectra in $Au+Au$ collisions as compared to data from STARstar-r and PHENIX phenix-r. See text for a detailed explanation.
• Figure 2: Azimuthal anisotropy in $Au+Au$ collisions as compared to the STARsnellings 4-particle cumulant result.
• Figure 3: Back-to-back correlations for charged hadrons with $p^{\rm trig}_T>p_T>2$ GeV/$c$, $p^{\rm trig}_T=4-6$ GeV/$c$ and $|y|<0.7$ in $Au+Au$ (lower curves) and $p+p$ (upper curves) collisions as compared to the STARstar-c data.
• Figure 4: The suppression factor for hadron-triggered fragmentation functions in central (0-5%) $Au+Au$ (d+Au) collisions as compared to the STAR data star-c.