Width of the Delta the resonance in nuclei

Abstract

In this work we evaluate the imaginary part of the isobar Δ self-energy Σ Δ from the two-body absorption process Δ+N→2N. This contribution is calculated using a recently developed nonrelativistic scheme, which allows for an evaluation of the self-energy with a basis of single-particle states appropriate for both bound hole states and for particle states in the continuum. In order to test the medium dependence of the self-energy, we calculate the two-body absorption term Σ A 2 Δ for several finite nuclei with N=Z, i.e., 16 O , 40 Ca , and 100 Sn . The resulting self-energy, which is energy dependent and nonlocal, is compared with a simple parametrization derived from nuclear matter.