Size effect in the deexcitation of hot nuclei

This paper aims at comparing the deexcitation mechanism of heavy and light hot nuclei. Two experimental samples of events corresponding to two systems differing mostly by their total mass (Au and Ca) are thus compared with two types of statistical model (instantaneous multifragmentation and binary sequential decay). The sizes of the nuclei contained in the two samples are different, but the constraints which characterize them are very similar. The first sample (Au+Cu at 600 MeV/nucleon) was obtained using the ALADIN spectrometer at SIS and the second one (Ca+Cu at 35 MeV/nucleon) using the AMPHORA multidetector at SARA. The same rigorous analysis protocol was used to make the four comparisons between experimental and simulated data. It is shown that the Au decay can only be reproduced by the multifragmentation codes (MMMC, Berlin, and SMM, Copenhagen-Moscow) and the Ca decay exclusively by the sequential emission code (GEMINI). {copyright} {ital 1996 The American Physical Society.}