Mass yield distributions for 1 GeV proton-induced nuclear reactions on Ni and Ag

For 1 GeV proton-induced reactions on Ni and Ag the inclusive mass spectra covering a wide range of masses are analyzed with a two-step statistical multifragmentation model which considers the secondary decay of the primordial fragments. It is found that the yield of lighter clusters can only be reproduced by considering the evaporation processes. The experimentally observed U-shaped mass spectra are described by essentially one parameter - the temperature of about 6 MeV. The power-law fit gives an exponent about one unit lower than the critical one.