title: Nuclear magnetic moment of the 57Cu ground state.
abstract: The nuclear magnetic moment of the ground state of (57)Cu(Iota(pi) = 3/2(-), T(1/2) = 196.3 ms) has been measured to be /mu((57)Cu)/ = (2.00 +/- 0.05)mu(N) using the beta-NMR technique. Together with the known magnetic moment of the mirror partner (57)Ni, the spin expectation value was extracted as <Sigmasigma(z)> = -0.078 +/- 0.13. This is the heaviest isospin mirror T = 1/2 pair above the (40)Ca region for which both ground state magnetic moments have been determined. The discrepancy between the present results and shell-model calculations in the full f p shell giving mu((57)Cu) approximately 2.4mu(N) and <Sigmasigma(z)> approximately 0.5 implies significant shell breaking at (56)Ni with the neutron number N = 28.
authors.affiliation: National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, 48824, USA.
authors.forename: K
authors.initials: K
authors.lastname: Minamisono
authors.forename: P F
authors.initials: PF
authors.lastname: Mantica
authors.forename: T J
authors.initials: TJ
authors.lastname: Mertzimekis
authors.forename: A D
authors.initials: AD
authors.lastname: Davies
authors.forename: M
authors.initials: M
authors.lastname: Hass
authors.forename: J
authors.initials: J
authors.lastname: Pereira
authors.forename: J S
authors.initials: JS
authors.lastname: Pinter
authors.forename: W F
authors.initials: WF
authors.lastname: Rogers
authors.forename: J B
authors.initials: JB
authors.lastname: Stoker
authors.forename: B E
authors.initials: BE
authors.lastname: Tomlin
authors.forename: R R
authors.initials: RR
authors.lastname: Weerasiri