  A simplified, though realistic, model describing two receding and
accelerating fission fragments, due to their mutual Coulomb repulsion, shows
that fission fragments share excitation energy well after they ceased to
exchange nucleons. This mechanism leads to a lower total kinetic energy of the
fission fragments, particularly if the pygmy resonances in the fission
fragments are excited. Even though the emphasis here is on fission, similar
arguments apply to fragments in heavy-ion reactions.
