[paper] Doubly-magic nature of ⁵⁶Ni: Measurement of the ground state nuclear magnetic dipole moment of ⁵⁵Ni

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 (I^π=3/2^–, T_1/2=204 ms) has been deduced to be |&mul(⁵⁵Ni)|=(0.976&plusminus;0.026) μ_N 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 <Σσ_z>=0.91&plusminus;0.07. The <Σσ_z> shows a trend similar to that established in the sd shell. The present theoretical interpretations of both &mul(⁵⁵Ni) and <Σσ_z> for the T=1/2, A=55 mirror partners support the softness of the ⁵⁶Ni core.

Tags: 55Nib-NMRpaperPRCshell modelspin expectation value