Vaporization and multifragmentation in the reaction 1.2 GeV (p)over-bar plus Cu and Ag

Reactions of 1.2 GeV antiprotons with Cu and Ag targets have been studied. It was found that in such reactions, excitation energies are generated in e xcess of the total binding energy of the nuclei involved. Accordingly, one observes in these reactions the onset of vaporization and multifragmentatio n processes. In the (p) over bar + Cu reaction, the vaporization is observe d to set in at about 7.5 MeV/nucleon. However, its probability remains rela tively small and below 15% up to the highest excitation energies identified in the present studies (approximately 15 MeV/nucleon). The threshold excit ation energy for multifragmentation processes, defined as the detection of at least 3 intermediate mass fragments, is observed at about 3 MeV/nucleon for both studied reactions. Multifragmentation is seen to account for no mo re than approximately 5% and 20% of the corresponding inclusive yield for C u and Ag targets, respectively. (C) 2000 Elsevier Science B.V. All rights r eserved.