Dynamical and many-body correlation effects in the kinetic energy spectra of isotopes produced in nuclear multifragmentation.

The properties of the kinetic energy spectra of light isotopes produced in the breakup of a nuclear source and during the deexcitation of its products are examined. The initial stage, at which the hot fragments are created, is modeled by the Statistical Multifragmentation Model, whereas the Weisskopf-Ewing evaporation treatment is adopted to describe the subsequent fragment deexcita- tion, as they follow their classical trajectories dictated by the Coulomb repulsion among them. The energy spectra obtained are compared to available experimental data. The influence of the fusion cross-section entering into the evaporation treatment is investigated and its influence on the qual- itative aspects of the energy spectra turns out to be small. Although these aspects can be fairly well described by the model, the underlying physics associated with the quantitative discrepancies remains to be understood.