Isobaric-Analog States inSc49

Abstract

Cross sections for the elastic scattering of protons by ${\mathrm{Ca}}^{48}$ have been measured at laboratory angles of 90°, 120°, and 160° for bombarding energies from 1.3 to 7.0 MeV. Prominent anomalies were observed in the excitation curves at c.m. proton energies of 1.935±0.003, 1.945±0.003, 3.86±0.03, 5.952±0.005, and 5.994±0.005 MeV. These anomalies indicate the positions of states in the compound nucleus ${\mathrm{Sc}}^{49}$ that are isobaric analogs of the ground state and excited states of ${\mathrm{Ca}}^{49}$. An analysis of these data and a comparison with the ${\mathrm{Ca}}^{48}(d, p){\mathrm{Ca}}^{49}$ results are presented. A value of 7.090±0.006 MeV for the ${\mathrm{Ca}}^{49}$-${\mathrm{Sc}}^{49}$, Coulomb energy difference is obtained from the observed proton bombarding energy for the ground-state analog. All the known Coulomb energies for the odd Ca and Sc isotopes have been analyzed in terms of a simple model using single-particle wave functions in a Woods-Saxon well, and are interpreted in terms of charge radii.