Configuration mixing in Mg28 and the Mg26(t,p)Mg28 reaction

Author(s): McNeel, DG; Wuosmaa, AH; Kuvin, SA; Smith, J; Back, BB; Chen, J; Hoffman, CR; Kay, BP; Wilson, GL; Sharp, DK; Clark, RM; Crawford, HL; Fallon, P; Macchiavelli, AO | Abstract: We have studied the Mg26(t,p)Mg28 reaction. The nucleus Mg28 lies between Mg24 and Mg32, the latter of which is central to the "island of inversion"characterized by low-lying neutron fp-shell configurations. The present results show that the second-excited 0+ state in Mg28 contains large fp-shell occupation for the neutrons. The experiment was performed in inverse kinematics using the HELIcal Orbit Spectrometer (HELIOS) at Argonne National Laboratory. Shell-model calculations using the SDPF-MU interaction yielded level energies and two-neutron transfer amplitudes that were used in one-step distorted-wave Born approximation calculations to provide theoretical predictions of the proton angular distributions. In many, but not all cases, the data were in good agreement with theoretical predictions.