Doubly-magic nature of 56Ni: measurement of the ground state nuclear magnetic dipole moment of 55Ni

Abstract

The nuclear magnetic moment of the ground state of ${}^{55}$Ni ($I^{\pi }=3/2^{-},T_{1/2}=204$ ms) has been deduced to be $|\mu$^{55}Ni)$|=(0.976\pm 0.026)$ ${\mu }_N$ using the $\beta$-NMR technique. Results of a shell model calculation in the full \textit{fp} shell model space with the GXPF1 interaction reproduce the experimental value. Together with the known magnetic moment of the mirror partner ${}^{55}$Co, the isoscalar spin expectation value was extracted as $<\sum {\sigma }_z>=0.91\pm 0.07$. The $<\sum {\sigma }_z>$ shows a similar trend as that established in the \textit{sd} shell. The present theoretical interpretations of both $\mu {(}^{55}$Ni) and $<\sum {\sigma }_z>$ for the $T=1/2$, A=55 mirror partners support the softness of the ${}^{56}$Ni core.

arXiv comment13 pages, 1 figure, accepted for publication in Phys. Rev. C

References in corpus (3)

• New effective interaction for $pf$-shell nuclei and its implications for the stability of the $N$=$Z$=28 closed core
• Nuclear Magnetic Moment of the 57Cu Ground State
• Fast switching NMR system for measurements of ground-state quadrupole moments of short-lived nuclei

Cited by in corpus (5)

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• Charge radii of ${}^{55,56}$Ni reveal a surprisingly similar behavior at $N=28$ in Ca and Ni isotopes
• Nuclear DFT analysis of electromagnetic moments in odd near doubly magic nuclei
• $\mathcal{F}t$ values of the mirror $\beta$ transitions and the weak magnetism induced current in allowed nuclear $\beta$ decay
• One-proton and one-neutron knockout reactions from $N=Z=28$ ${}^{56}$Ni to the $A=55$ mirror pair ${}^{55}$Co and ${}^{55}$Ni