Two-Body Propagators with Dynamic Effective Interactions in a Many Fermion Medium. 2. S Channel

1977
23 pages
Published in:
  • Annals Phys. 104 (1977) 251-273

Citations per year

197719871997200720163012
Abstract: (Elsevier)
In open-shell nuclear structure calculations collective excitations of the closed-shell core play an important role. When the energies of these excitations are comparable to the spread of energies in the model space a dynamic treatment of the core states is essential. In a Green function formulation dynamic core states, represented by particle-hole phonons, are included in the effective interaction of the s -channel integral equation for the fourfermion vertex function Γ. The solution of the equation is obtained analytically and from it the s -channel two-body propagator K is calculated. The structure of the propagator K reveals that, in addition to poles corresponding to the normal shell model states, many new poles of K are obtained. These correspond to two-particle- n -phonon configurations. Furthermore, it is shown that, due to the phonons, correlations of the ground state are induced in the calculation of the propagator K . The difference between these correlations and the well-known particle-particle-RPA correlations also included in the formalism is pointed out. The expressions derived can easily be handled numerically. In the calculations the physical states of single-particle and single-hole nuclei can be incorporated by an appropriate dressing of the single-fermion Green function.
  • PROPAGATOR: TWO-PARTICLE
  • NUCLEAR REACTION
  • STATISTICAL MECHANICS
  • SOLIDS
  • MANY-BODY PROBLEM: FERMION
  • EXCHANGE: BOSON
  • VERTEX FUNCTION: SCATTERING AMPLITUDE
  • SCATTERING AMPLITUDE: VERTEX FUNCTION
  • SYMMETRY: CROSSING
  • QUANTUM MECHANICS: SCATTERING