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

A. Fernández (1) , A. Jungclaus (1) , P. Doornenbal , M.A. Bentley , S.M. Lenzi (2) , D. Rudolph , F. Browne (3) , M.L. Cortés , T. Koiwai , R. Taniuchi (3) , V. Vaquero (1) , K. Wimmer , T. Arici , N. Imai (4) , N. Kitamura , Radomira Lozeva (5, 6) , B. Longfellow , B. Mauss (4) , D.R. Napoli , M. Niikura , X. Pereira-Lopez , S. Pigliapoco , A. Poves , F. Recchia , P. Ruotsalainen , H. Sakurai , S. Uthayakumaar , R. Wadsworth , R. Yajzey

1 CSIC - Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain]
2 INFN, Sezione di Padova - Istituto Nazionale di Fisica Nucleare, Sezione di Padova
3 RIKEN RNC - RIKEN Nishina Center for Accelerator-Based Science [Wako]
4 RIKEN - RIKEN - Institute of Physical and Chemical Research [Japon]
5 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
6 Université Paris-Saclay

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 yrast sequence. This turns 56Zn into the heaviest nucleus in which excited states are known. The excitation-energy differences between these levels and the isobaric analogue states in the 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 , 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.

Domaines: Physique [physics]

A. Fernández, A. Jungclaus, P. Doornenbal, M.A. Bentley, S.M. Lenzi, et al.. Mirror energy differences above the 0f7/2 shell: First γ-ray spectroscopy of the T = −2 nucleus 56Zn. Physics Letters B, 2021, 823, pp.136784. ⟨10.1016/j.physletb.2021.136784⟩. ⟨hal-03448623⟩