INDRA collaboration

Physics Letters B 432 (1998) 29–36

Preprint

Thermal scaling (Arrhenius law for an “elementary” probability p of binomial function) and reducibility in intermediate mass fragments (IMF’s) production are examined for data of the reaction Image XeImage Image Sn at 50 MeV/u. The study of the longitudinal velocities and of the average transverse energies of the IMF’s contradicts the assumption that the total transverse energy of all detected particles Et is related to a well defined temperature. The separation of Et into the total transverse energy of light charged particles (Z=1,2 ) and that of IMF’s elucidates the algorithm which induces a linear behavior of log(1/p) versus 1/sqrt(Et) . Even in the case of a single thermalized source, calculations based on a sequential statistical model show that the Arrhenius law cannot be observed if Et is taken as an estimation of the thermal energy.