An effective dynamic interaction for the two-particle propagator

Abstract

Abstract. In nuclear structure calculations the collective excitations of the core introduce dynamic effects in the interaction between particles. Under the restriction of including forward-going contributions only, it is shown that the two-particle propagator which yields the spectra and two-particle transfer strengths of nuclei with two nucleons outside a closed shell, can be written in a Dyson-like equation in which a two-particle self-energy or dynamic effective interaction A is introduced. An expression for A is given in terms of the irreducible vertex part of the Bethe-Salpeter equation and partial summations for A using phonon exchange interactions to represent the core-polarization diagrams, are discussed. The single-particle propagators are also dressed with phonon-exchange contributions.

Quasiparticle time blocking approximation within the framework of generalized Green function formalism

“…The idea of the method is similar to that used in the other methods developed earlier for the solution of the analogous problems in Refs. [20] (ph-channel BSE) and [21,22,23] (pp-channel BSE). However, the MCDD differs from the aforementioned methods in some details, in particular concerning the treatment of the GSC2.…”

Mode coupling theory for the description of two particle-two hole states of208Pb

“…5). The approximations shown in Figures 4, 5 neglect, however, the fact that while the one phonon is "travelling", the other particle hole pair can also correlate to give a second phonon (this is indicated by the dotted lines) as is discussed for instance by Hahne and Heiss [8]. It would be clearly an inconsistency to leave out the correlations in one particle hole pair whereas they are taken into account in the other.…”