The role of jet quenching in the p-bar >= pi- anomaly at RHIC

Abstract

Preliminary PHENIX data on $Au+Au$ reactions at $\sqrt{s}= 130$ AGeV suggest that $\bar{p}$ yields may exceed $\pi^-$ at high $p_{\rm T} > 2$ GeV/c. We propose that jet quenching in central collisions suppresses the hard PQCD component of the spectra in central $A+A$ reactions, thereby exposing a novel non-perturbative component of baryon dynamics. We suggest that baryon junctions provide a possible explanation of the anomalous component. We predict that the $\bar{p} \geq \pi^-$ anomaly is limited to a finite $p_{\rm T}$ window and decreases with increasing impact parameter.