A very recent pion inelastic scattering experiment has revealed the existence of strong spin flip $E1\mathrm{}$ resonances in light nuclei. The data are particularly impressive in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ where two strong peaks are observed in the vicinity of the giant dipole resonance. We present here the first large scale shell model calculation of such electric spin excitations in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and discuss their admixture and influence on other $S=0\mathrm{}$ states.

NUCLEAR STRUCTURE Spin flip $E1\mathrm{}$, shell model calculation.

• Received 2 September 1983

DOI:https://doi.org/10.1103/PhysRevC.28.2571