The odd-odd fp-shell nucleus Sc52 was investigated using in-beam γ-ray spectroscopy following secondary fragmentation of a V55 and Cr57 cocktail beam. Aside from the known γ-ray transition at 674(5) keV, a new decay at Eγ=212(3) keV was observed. It is attributed to the depopulation of a low-lying excited level. This new state is discussed in the framework of shell-model calculations with the GXPF1, GXPF1A, and KB3G effective interactions. These calculations are found to be fairly robust for the low-lying level scheme of Sc52 irrespective of the choice of the effective interaction. In addition, the frequency of spin values predicted by the shell model is successfully modeled by a spin distribution formulated in a statistical approach with an empirical, energy-independent spin-cutoff parameter. © 2006 The American Physical Society.

The two-proton knockout reaction Be9(Ti54,Ca52+γ) has been studied at 72 MeV/nucleon. Besides the strong feeding of the Ca52 ground state, the only other sizeable cross section proceeds to a 3- level at 3.9 MeV. There is no measurable direct yield to the first excited 2+ state at 2.6 MeV. The results illustrate the potential of such direct reactions for exploring cross-shell proton excitations in neutron-rich nuclei and confirms the doubly-magic nature of Ca52. © 2006 The American Physical Society.

The β-decay and isomeric properties of 54Sc, 50K and 53Ca are presented, and their implications with respect to the goodness of the N = 32 sub-shell closure discussed.