Mirror energy differences above the 0f7/2 shell: First γ-ray spectroscopy of the Tz = −2 nucleus 56Zn

• Published in: Physics letters. B Vol. 823; p. 136784
• Main Authors: Fernández, A., Jungclaus, A., Doornenbal, P., Bentley, M.A., Lenzi, S.M., Rudolph, D., Browne, F., Cortés, M.L., Koiwai, T., Taniuchi, R., Vaquero, V., Wimmer, K., Arici, T., Imai, N., Kitamura, N., Longfellow, B., Lozeva, R., Mauss, B., Napoli, D.R., Niikura, M., Pereira-Lopez, X., Pigliapoco, S., Poves, A., Recchia, F., Ruotsalainen, P., Sakurai, H., Uthayakumaar, S., Wadsworth, R., Yajzey, R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-12-2021; Elsevier
• Subjects: Fysik; isospin symmetry; mirror nuclei; Natural Sciences; Naturvetenskap; nucleon removal; Physical Sciences; radioactive ion beams; shell-model calculations; Subatomic Physics; Subatomär fysik
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2021.136784

Excited states in 56Zn were populated following one-neutron removal from a 57Zn beam impinging on a Be target at intermediate energies in an experiment conducted at the Radioactive Isotope Beam Factory at RIKEN. Three γ rays were observed and tentatively assigned to the 6+→4+→2+→0+ yrast sequence. This turns 56Zn into the heaviest Tz=−2 nucleus in which excited states are known. The excitation-energy differences between these levels and the isobaric analogue states in the Tz=+2 mirror partner, 56Fe, are compared with large-scale shell-model calculations considering the full pf valence space and various isospin-breaking contributions. This comparison, together with an analysis of the mirror energy differences in the A=58, Tz=±1 pair 58Zn and 58Ni, provides valuable information with respect to the size of the monopole radial and the isovector multipole isospin-breaking terms in the region above doubly-magic 56Ni.