Institut de recherche sur les lois fondamentales de l'Univers

Results on projectile fragment-fragment coincidences in the forward direction and for the 
reaction 40Ar+27Al at 44 A.MeV are presented and compared with the predictions of two 
different entrance channel models, a two-body and a three-body mechanism both followed 
by a binary multisequential decay including fission. This analysis shows that many features 
of the projectile decay products are well accounted for by the binary multisequential decay 
model. However the results depend critically upon the initial masses and excitation energies 
of the primary projectile fragments. In this respect, the three-body approach underestimates 
the excitation energy imparted to the primary fragments whereas the two-body scenario 
overestimates it. The present data put strong constraints on the initial excitation energy 
imparted to the primary fragments which appears to be intermediate between the predictions 
of the two models.