Doubly-magic nature of 56Ni: Measurement of the ground state nuclear magnetic dipole moment of 55Ni
J.S. Berryman et al.
doi: 10.1103/PhysRevC.79.064305
The nuclear magnetic moment of the ground state of 55Ni (Iπ=3/2–, T1/2=204 ms) has been deduced to be |&mul(55Ni)|=(0.976&plusminus;0.026) μN using the β-ray detecting nuclear magnetic resonance technique. Results of a shell model calculation in the full fp shell model space with the GXPF1 interaction reproduce the experimental value. Together with the known magnetic moment of the mirror partner 55Co, the isoscalar spin expectation value was extracted as <Σσz>=0.91&plusminus;0.07. The <Σσz> shows a trend similar to that established in the sd shell. The present theoretical interpretations of both &mul(55Ni) and <Σσz> for the T=1/2, A=55 mirror partners support the softness of the 56Ni core.