Isobaric analog state energy in deformed nuclei: A toy model

A formula to evaluate the effects of a general deformation on the Coulomb direct contribution to the energy of the isobaric analog state (IAS) is presented and studied via a simple yet physical model. The toy model gives a reasonable account of microscopic deformed Hartree-Fock-Bogoliubov (HFB) calculations in a test case, and provides a guidance when predicting unknown IAS energies. Thus, deformed HFB calculations, to predict the IAS energies, are performed for several neutron-deficient medium-mass and heavy nuclei which are now planned to be studied experimentally.