High-Resolution Study of Isobaric Analog Resonances inNa23

Abstract

Excitation functions for the elastic scattering of protons by ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ have been measured at 90°, 105°, 120°, 135°, 150°, and 160° from 0.8 to 3.13 MeV, and for the reaction ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}(p, p^{\prime }){}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}_{}^{*}{}_{}{}^{}$ (first excited state), at 90°, 120°, and 150° from 2.0 to 3.13 MeV, with an average energy resolution of about 250 eV. Spins, parities, and partial and total widths have been extracted for the large majority of the 76 resonances observed. Two isobaric analog states, those of the sixth and seventh excited states of ${}_{}{}^{23}{}_{}{}^{}\mathrm{Ne}$, have been identified. Both analogs are evidenced as fragmentations of the broad $T_{>}$ states into enhancement of the background $T_{<}$ states. A sum rule applied to the individual fine-structure widths implies spectroscopic factors in agreement with those extracted from ($d, p$) stripping measurements on ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$.