HeatingA197uNuclei with8GeV/cAntiproton andπ−Beams

Abstract

Comparison of the heating effect produced by 8 $\mathrm{GeV}/c$ ${\ensuremath{\pi}}^{\ensuremath{-}}$ and antiproton beams incident on ${}^{197}\mathrm{Au}$ nuclei has been conducted with the Indiana silicon sphere $4\ensuremath{\pi}$ detector array. Event reconstruction indicates formation of thermal-like heavy residues with excitation energies up to 1.7 GeV. Enhanced energy deposition is observed for antiprotons relative to negative pions. For events with excitation energies that exceed 1000 MeV, there is a $50%$ increase in cross section for the antiproton beam relative to the ${\ensuremath{\pi}}^{\ensuremath{-}}$ beam. The predominant decay mode at these high excitation energies is multifragmentation in which three or more $Z\ensuremath{\ge}3$ fragments are emitted.