ON NUCLEAR SINGLE-PARTICLE POTENTIALS (Ⅱ) THE NONHERMITIAN CHOICE
- Received Date: 1977-06-06
- Accepted Date: 1900-01-01
- Available Online: 1978-02-05
Abstract: The cancellation properties of the nonhermitian single-particle (SP) potential uαβ=Mαβ (εβ) [or Mαβ(εα)] according to the principle of maximal cancellation of perturbation diagrams are investigated in detail. The mass operator Mαβ(ω) is separated into two parts Mαβon (ω) and Mαβoff (ω) as usual, however, a new criterion for their definition will be proposed. It is shown that the exact mass operator insertion is equal to the sum of the following three types of terms:(1) terms contributed by the poles of Mαβoff(ω). They are truly non-factorizable and must be considered separately,(2) terms which can be cancelled to all orders by the nonhermitian choice uαβ=Mαβ (εβ) [or Mαβ(εα)]. Hence, they serve to define uαβ,(3) the remaining terms, which can be summed to all orders in a simple way and may be interpreted as amplitude renormalization of the SP Green function.In order to illustrate the usefulness of the above results, we have considered the renormalized random phase approximation (RRPA) for the particle-hole Green function as an example. Related formulae are derived. In RRPA, not only the SP propagator renormalization which includes all the effects except those contributed by the poles of Mαβoff (ω), but also the off energy shell property of the G matrix elements have been taken into account.