One-particle excitations outside the Ti-54 semi-magic core: The V-55 and Ti-55 yrast structures

摘要

The level structures of V-55 and Ti-55, the two nuclei with a single nucleon outside the semi-magic Ti-54(22)32 core, have been investigated in order to provide new tests of full pf-shell calculations with the GXPFIA interaction. The addition of a proton does not appear to affect the N = 32 shell Gap significantly. although comparisons between calculations and experiment at high spins (I-pi >= 21/2(-)) indicate the need for a larger model space for an accurate description of the data in this regime. The energy separation between the vp(1/2) and vf(5/2) orbitals in neutron-rich Ti isotopes is not large enough to result in an N = 34 shell gap. However, comparisons between the Ti-55 data and the calculations argue for the presence of a sizable N = 34 gap in Ca-54. (C) 2007 Elsevier B.V. All rights reserved.