J=O+ STATES IN CA-40 AND CA-42

An attempt has been made to understand the low-lying spectra of 0+ states in Ca40 and Ca42, without having to introduce configurations with a very high number of holes. The analysis of Ca40 includes 0p-0h, 2p-2h, and 4p-4h configurations, with the particles and holes restricted to the 1f72 and 1d32 orbitals, respectively. The effects of higher orbitals are simulated by lowering the 1f72-1d32 single-particle splitting. The model reproduces all the known 0+ levels in Ca40 with remarkable accuracy. The calculation in Ca42 includes only the 2p-0h and 4p-2h configurations, and the same matrix elements used in the analysis of Ca40. Again all the known 0+ states are reproduced, including the group between 5.85 and 6.70 MeV. These states are predominantly of 4p-2h nature, with the four particles coupled to their maximum possible isospin. © 1969 The American Physical Society.