Au+Au Collisions: the Suppression of High Transverse Momentum in Neutral pion Spectra

Abstract

Au+Au, $\sqrt{s} = 200$ A GeV measurements at RHIC, obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors, have all indicated a suppression of production, relative to an appropriately normalized NN level. For central collisions and vanishing pseudo-rapidity these experiments indicate a considerable reduction, relative to that nominally expected from equivalent PP measurements, in charged and particle production, especially at mid- to large transverse momenta. In the PHENIX experiment similar behavior has been reported for $\pi^0$ spectra. In a recent work \cite{luc4brahms} on the presumably simpler D+Au interaction, to be considered perhaps as a tune-up for Au+Au, we reported on a hadronic cascade mechanism which can explain the observed moderatereduced $p_\perp$ suppression at higher pseudorapidity as well as the Cronin enhancement at mid- rapidity. Here we present the extension of this work to the more massive ion-ion collisions.