  The question of how the scattering cross section changes when the spectra of
the colliding nuclei have low-excitation particle-emitting resonances is
explored using a multi-channel algebraic scattering (MCAS) method. As a test
case, the light-mass nuclear target 8Be, being particle-unstable, has been
considered. Nucleon-nucleus scattering cross sections, as well as the spectra
of the compound nuclei formed, have been determined from calculations that do,
and do not, consider particle emission widths of the target nuclear states. The
resonant character of the unstable excited states introduces a problem because
the low-energy tails of these resonances can intrude into the sub-threshold,
bound-state region. This unphysical behaviour needs to be corrected by
modifying, in an energy-dependent way, the shape of the target resonances from
the usual Lorentzian one. The resonance function must smoothly reach zero at
the elastic threshold. Ways of achieving this condition are explored in this
paper.
