Pion-reabsorption effect on pion spectra in high-energy heavy-ion collisions.

Abstract

Cascade-model calculations are extended to study the pion energy spectra in high-energy heavy-ion collisions of heavy systems. It is found that pion reabsorption (\ensuremath{\pi}+N\ensuremath{\rightarrow}\ensuremath{\Delta}) is essential in explaining the difference between the energy slopes for pions and protons. This pion-reabsorption effect becomes more and more important as the mass number increases and reproduces even the observed falloff of the energy slopes (temperatures) for pions in the collisions of heavier nuclei. We show also the average pion multiplicities with mass number.