A coexistence model for ¹⁸F

Abstract

Three intrinsic four-particle-two-hole core-deformed states, labelled by the K-quantum number of the holes, are introduced to aid in describing the low-lying T = 0 even-parity levels in ¹⁸F. Since states of good angular momentum projected from only two of these three states can admix with the even-J two-particle states, the paucity of the even-J relative to the odd-J states can be explained in this fashion. The emphasis is on the reproduction of the empirical spectra using realistic potentials. However, calculations of the E2 transition probabilities and comparison of results with particle transfer data serve as tests of the model. A notable feature is that the T = 0 matrix elements between the 2p and 4p2h states are found to be considerably smaller than the T = 1 ones.