A model for the mass-number independence of the antiproton annihilation onnuclei at low energies

A simple model explaining the recently observed approximate independence of the annihilation cross section on light nuclei at low energies is proposed . The salient idea is based on the realization that the pis from the annihi lation on a nucleon have energies in the region of the Delta (1232) resonan ce. The coherent propagation of these pis through the excitation of several Delta resonances results in a destructive interference explaining why the annihilation of antiprotons in nuclei is suppressed. This model suggests a very effective way to produce "Delta matter" with several A resonances in i nteraction. (C) 2001 Elsevier Science B.V. All rights reserved.