New evidence for a subshell gap at N = 32

An 879.9(2) keV γ-ray transition has been identified following the β decay of 58V and assigned as the 21+ → 01+ transition in 58Cr34. A peak in the energies of the first excited 2+ states for the even-even chromium isotopes is now evident at 56Cr32, providing empirical evidence for a significant subshell gap at N = 32. The appearance of this neutron subshell closure for neutron-rich nuclides may be attributed to the diminished π 1 f7/2-v1f5/2 monopole proton-neutron interaction as protons are removed from the 1 f7/2 single-particle orbital. © 2001 Elsevier Science B.V. All rights reserved.