Estimating ground state multiplet splitting, based on the masses of nuclei
The pairing interaction between nucleons has a strong effect on the structure of an atomic nucleus. The most precise estimate of the magnitude of pairing forces is obtained by determining it for every isotope, based on the masses of the nuclei. The quality of this estimate is characterized by the degree of reconstruction for levels of the nucleus ground state multiplet (GSM). In this work, GSMs for even-even nuclei with pairs of identical nucleons over a filled core are considered on the basis of the delta interaction. Calculations of the GSM structure for isobar nuclei A = 42 and A = 134 show that analyzing GSM in the case of np pairing yields additional information on the correlation between isoscalar and isovector components in the structure of pairing forces.