Experimental evidence for 56Ni-core breaking from the low-spin structure of the N=Z nucleus 58Cu

Abstract

Low-spin states in the odd-odd N=Z nucleus 58Cu were investigated with the 58Ni(p,n gamma)58Cu fusion evaporation reaction at the FN-tandem accelerator in Cologne. Seventeen low spin states below 3.6 MeV and 17 new transitions were observed. Ten multipole mixing ratios and 17 gamma-branching ratios were determined for the first time. New detailed spectroscopic information on the 2+,2 state, the Isobaric Analogue State (IAS) of the 2+,1,T=1 state of 58Ni, makes 58Cu the heaviest odd-odd N=Z nucleus with known B(E2;2+,T=1 --> 0+,T=1) value. The 4^+ state at 2.751 MeV, observed here for the first time, is identified as the IAS of the 4+,1,T=1 state in 58Ni. The new data are compared to full pf-shell model calculations with the novel GXPF1 residual interaction and to calculations within a pf5/2 configurational space with a residual surface delta interaction. The role of the 56Ni core excitations for the low-spin structure in 58Cu is discussed.

15 pages, 7 figures, submitted to Phys. Rev. C

References in corpus (9)

• Effective interaction for pf-shell nuclei
• Calculated corrections to superallowed Fermi beta decay: New evaluation of the nuclear-structure-dependent terms
• Isobaric multiplet yrast energies and isospin non-conserving forces
• Pairing and symmetry energy in N \simeq Z nuclei
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• Band termination in the N=Z Odd-Odd Nucleus 46V
• Quasi-Deuteron Configurations in odd-odd N=Z nuclei
• Quasideuteron states with deformed core
• Quasideuteron configurations in 46V and 58Cu

Cited by in corpus (8)

• New effective interaction for $pf$-shell nuclei and its implications for the stability of the $N$=$Z$=28 closed core
• Magnetic dipole moment of 57,59Cu measured by in-gas-cell laser spectroscopy
• Shell-model description of monopole shift in neutron-rich Cu
• Isovector spin-singlet (T=1, S=0) and isoscalar spin-triplet (T=0, S=1) pairing interactions and spin-isospin response
• Three-body model calculations for N=Z odd-odd nuclei with T=0 and T=1 pairing correlations
• Competition between $T$=1 and $T$=0 pairing in $pf$-shell nuclei with $N=Z$
• Deformation effects on the coexistence between neutron-proton and particle like pairing in N=Z medium mass nuclei
• Role of cross-shell excitations in the reaction 54Fe(d_pol,p)55Fe