Quenching of high $p_\perp$ hadrons by (pre--)hadronic FSI at RHIC

Abstract

Recently we have conjectured that (in-)elastic collisions of (pre-)hadronic high momentum states with the bulk of hadrons in the late fireball might substantially account for the attenuation of the high transverse momentum hadrons at RHIC. The potential hadronic attenuation has therefore to be addressed in further detail before definite conclusions on possible QCD effects in a deconfined QGP phase can be drawn with respect to the materializing jets. From our transport studies we find that the interactions of fully formed hadrons are practically negligible in central Au+Au collisions at \sqrt s = 200 GeV for $p_\perp\geq 6 GeV$, but have some importance for the shape of the ratio $R_{AA}$ at lower $p_\perp$ ($\leq 6 GeV$). However, a significant part of the large suppression seen experimentally is attributed to inelastic interactions of 'leading' jet-like pre-hadrons with the dense hadronic environment. In addition, we also show within this scenario first (preliminary) results of near-side and far-side correlations of high $p_\perp$ particles from central Au+Au collisions at $\sqrt{s}$ = 200 GeV. It turns out that the near-side correlations are unaltered -- in accordance with experiment -- whereas the far-side correlations are suppressed by $\sim$ 60%. Since the experimental observation is a nearly complete disappearance of the far-side jet there should be some additional and earlier partonic interactions in the dense and possibly colored medium.

8 Latex pages including 10 eps figures and IOP style files. Talk given at the 17th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter 2004, Oakland, CA USA, 11-17 Jan 2004. To appear in J. Phys. G