- Spieker, M
- Weisshaar, D
- Gade, A
- Brown, BA
- Adrich, P
- Bazin, D
- Bentley, MA
- Brown, JR
- Campbell, CM
- Diget, CA
- Elman, B
- Glasmacher, T
- Hill, M
- Longfellow, B
- Pritychenko, B
- Ratkiewicz, A
- Rhodes, D
- Tostevin, JA
- et al.

New experimental data obtained from γ-ray tagged one-neutron and one-proton knockout from Co55 are presented. A candidate for the sought-after T=1,Tz=0,Jπ=6+ state in Co54 is proposed based on a comparison to the new data on Fe54, the corresponding observables predicted by large-scale-shell-model (LSSM) calculations in the full fp-model space employing charge-dependent contributions, and isospin-symmetry arguments. Furthermore, possible isospin-symmetry breaking in the A=54, T=1 triplet is studied by calculating the experimental c coefficients of the isobaric mass multiplet equation (IMME) up to the maximum possible spin J=6 expected for the (1f7/2)-2 two-hole configuration relative to the doubly magic nucleus Ni56. The experimental quantities are compared to the theoretically predicted c coefficients from LSSM calculations using two-body matrix elements obtained from a realistic chiral effective field theory potential at next-to-next-to-next-to-leading order (N3LO).