The 30Mg(t, p)32Mg puzzle reexamined

Background: Competing interpretations of the results of a Mg-30(t, p)Mg-32 measurement populating the ground state and 0(2)(+) state in Mg-32, both limited to a two-state mixing description, have left an open question regarding the nature of the Mg-32 ground state. Purpose: Inspired by recent shell-model calculations, we explore the possibility of a consistent interpretation of the available data for the low-lying 0(+) states in Mg-32 by expanding the description from two-level to three-level mixing. Methods: A phenomenological three-level mixing model of unperturbed 0p0h, 2p2h, and 4p4h states is applied to describe both the excitation energies in Mg-32 and the transfer reaction cross sections. Results: Within this approach, self-consistent solutions exist that provide good agreement with the available experimental information obtained from the Mg-30(t, p)Mg-32 reaction. Conclusion: The inclusion of the third state, namely the 4p4h configuration, resolves the puzzle that results from a two-levelmodel interpretation of the same data. In our analysis, the Mg-32 ground state emerges naturally as dominated by intruder (2p2h and 4p4h) configurations, at the 95% level.