  Experimental studies of fission induced in relativistic nuclear collisions
show a systematic enhancement of the excitation energy of the primary fragments
by a factor of ~ 2, before their decay by fission and other secondary
fragments. Although it is widely accepted that by doubling the energies of the
single-particle states may yield a better agreement with fission data, it does
not prove fully successful, since it is not able to explain yields for light
and intermediate mass fragments. State-of-the-art calculations are successful
to describe the overall shape of the mass distribution of fragments, but fail
within a factor of 2-10 for a large number of individual yields. Here, we
present a novel approach that provides an account of the additional excitation
of primary fragments due to final state interaction with the target. Our method
is applied to the 238U + 208Pb reaction at 1 GeV/nucleon (and is applicable to
other energies), an archetype case of fission studies with relativistic heavy
ions, where we find that the large probability of energy absorption through
final state excitation of giant resonances in the fragments can substantially
modify the isotopic distribution of final fragments in a better agreement with
data. Finally, we demonstrate that large angular momentum transfers to the
projectile and to the primary fragments via the same mechanism imply the need
of more elaborate theoretical methods than the presently existing ones.
