Mass and width of the $d^{\prime }$ resonance in nuclei

Abstract

We calculated the mass and width of the $d^{\prime }$ resonance inside nuclei within a nucleon-$\Delta$ model by including the self-energy of the $\Delta$ in the $N\Delta$ propagator. We found that in the nuclear medium the width of the $d^{\prime }$ is increased by one order of magnitude while its mass changes only by a few MeV. This broadening of the width of the $d^{\prime }$ resonance embedded in nuclei is consistent with the experimental observations so that the $d^{\prime }$ can be understood as a $N\Delta$ resonance. Thus, given the freedom between either isospin 0 or isospin 2 for the $d^{\prime }$, our results give weigth to the isospin-2 assignment.

Comments: 14 pages, RevteX type, 2 eps figures. To be published in Phys. Rev. C (September)