TOWARDS A FULLY SELF-CONSISTENT SPECTRAL-FUNCTION OF THE NUCLEON IN NUCLEAR-MATTER

We present a calculation of nuclear matter which goes beyond the usual quasiparticle approximation in that it includes part of the off-shell dependence of the self-energy in the self-consistent solution of the single-particle spectrum. The spectral function is separated in contri butions for energies above and below the chemical potential. For holes we approximate the spectral function for energies below the chemical potential by a delta function at the quasiparticle peak and retain the standard form for energies above the chemical potential. For particle s a similar procedure is followed. The approximated spectral function is consistently used at all levels of the calculation. Results for a m odel calculation are presented, the main conclusion is that, although several observables are affected by the inclusion of the continuum con tributions, the physical consistency of the model does not improve wit h the improved self-consistency of the solution method. This is in con trast to expectations based on the crucial role of self-consistency in the proofs of conservation laws.