DELTA-(1236) PROBABILITY IN THE GROUND-STATE OF THE NUCLEAR MANY-BODY SYSTEM

The probability of finding isobar configurations in the ground state of nuclear many-body systems is discussed for the deuteron, 16O and infinite nuclear matter. A method is presented which allows the calculation of these probabilities taking into account effects of single-particle wave function and two-particle correlations in a self-consistent way. Momentum-space transition potentials are used that avoid the approximations which are necessary for r-space calculations, such as (a) π- and ρ-range propagators and (b) the static limit at the vertices. This yields considerably smaller values for the probability of one-Δ excitations, while the probability of exciting two Δ simultaneously is almost the same as in the approximate treatment. © 1979.