title: Isomer Shift and Magnetic Moment of the Long-Lived 1/2^{+} Isomer in _{30}^{79}Zn_{49}: Signature of Shape Coexistence near ^{78}Ni.
abstract: Collinear laser spectroscopy is performed on the _{30}^{79}Zn_{49} isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life is confirmed, and the nuclear spins and moments of the ground and isomeric states in ^{79}Zn as well as the isomer shift are measured. From the observed hyperfine structures, spins I=9/2 and I=1/2 are firmly assigned to the ground and isomeric states. The magnetic moment μ (^{79}Zn)=-1.1866(10)μ_{N}, confirms the spin-parity 9/2^{+} with a νg_{9/2}^{-1} shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment μ (^{79m}Zn)=-1.0180(12)μ_{N} supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the N=50 shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state, δ⟨r_{c}^{2}⟩^{79,79m}=+0.204(6)  fm^{2}, providing first evidence of shape coexistence.
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: X F
authors.initials: XF
authors.lastname: Yang
authors.affiliation: Oliver Lodge Laboratory, Oxford Street, University of Liverpool, Liverpool L69 7ZE, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Wraith
authors.affiliation: School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: Xie
authors.affiliation: Oliver Lodge Laboratory, Oxford Street, University of Liverpool, Liverpool L69 7ZE, United Kingdom.|EN Department, CERN, CH-1211 Geneva 23, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Babcock
authors.affiliation: School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Billowes
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.|School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: M L
authors.initials: ML
authors.lastname: Bissell
authors.affiliation: Max-Plank-Institut für Kernphysik, D-69117 Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Blaum
authors.affiliation: Oliver Lodge Laboratory, Oxford Street, University of Liverpool, Liverpool L69 7ZE, United Kingdom.
authors.forename: B
authors.initials: B
authors.lastname: Cheal
authors.affiliation: School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: K T
authors.initials: KT
authors.lastname: Flanagan
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: R F
authors.initials: RF
authors.lastname: Garcia Ruiz
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Gins
authors.affiliation: Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Gorges
authors.affiliation: Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany.|Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland.
authors.forename: L K
authors.initials: LK
authors.lastname: Grob
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: H
authors.initials: H
authors.lastname: Heylen
authors.affiliation: Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany.|Institut für Kernchemie, Universität Mainz, D-55128 Mainz, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kaufmann
authors.affiliation: Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Kowalska
authors.affiliation: Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kraemer
authors.affiliation: Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Malbrunot-Ettenauer
authors.affiliation: Max-Plank-Institut für Kernphysik, D-69117 Heidelberg, Germany.|Institut für Kernchemie, Universität Mainz, D-55128 Mainz, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Neugart
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Neyens
authors.affiliation: Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Nörtershäuser
authors.affiliation: KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Papuga
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Sánchez
authors.affiliation: Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, 91406 Orsay, France.
authors.forename: D T
authors.initials: DT
authors.lastname: Yordanov