The nuclear magnetic moment of the ground state of 57Cu has been measured to be 2.00 +/- 0.05 nuclear magnetons (nm) using the beta-NMR technique. Together with the known magnetic moment of the mirror partner 57Ni, the spin extraction value was extracted as -0.78 +/- 0.13. This is the heaviest isospin T=1/2 mirror pair above the 40Ca region, for which both ground state magnetic moments have been determined. Shell model calculations in full fp shell giving mu(57Cu)~2.4 nm and <sigma_z> ~0.5 imply significant shell breaking at 56Ni with the neutron number N=28.
@article{arxiv.nucl-ex/0602016,
title = {Nuclear Magnetic Moment of the 57Cu Ground State},
author = {K. Minamisono and P. F. Mantica and T. J. Mertzimekis and A. D. Davies and M. Hass and J. Pereira and J. S. Pinter and W. F. Rogers and J. B. Stoker and B. E. Tomlin and R. R. Weerasiri},
journal= {arXiv preprint arXiv:nucl-ex/0602016},
year = {2009}
}