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Article
Report number	arXiv:1604.03316
Title	Isomer shift and magnetic moment of the long-lived 1/2$^{+}$ isomer in $^{79}_{30}$Zn$_{49}$: signature of shape coexistence near $^{78}$Ni
Author(s)	Yang, X.F. (KU Leuven, Dept. Phys. Astron.) ; Wraith, C. (Liverpool U.) ; Xie, L. (Manchester U.) ; Babcock, C. (Liverpool U. ; CERN) ; Billowes, J. (Manchester U.) ; Bissell, M.L. (KU Leuven, Dept. Phys. Astron. ; Manchester U.) ; Blaum, K. (Heidelberg, Max Planck Inst.) ; Cheal, B. (Liverpool U.) ; Flanagan, K.T. (Manchester U.) ; Garcia Ruiz, R. F. (KU Leuven, Dept. Phys. Astron.) ; Gins, W. (KU Leuven, Dept. Phys. Astron.) ; Gorges, C. (Darmstadt, Tech. Hochsch.) ; Grob, L.K. (Darmstadt, Tech. Hochsch. ; CERN) ; Heylen, H. (KU Leuven, Dept. Phys. Astron.) ; Kaufmann, S. (Darmstadt, Tech. Hochsch. ; Mainz U., Inst. Kernchem.) ; Kowalska, M. (CERN) ; Kraemer, J. (Darmstadt, Tech. Hochsch.) ; Malbrunot-Ettenauer, S. (CERN) ; Neugart, R. (Heidelberg, Max Planck Inst. ; Mainz U., Inst. Kernchem.) ; Neyens, G. (KU Leuven, Dept. Phys. Astron.) ; Nörtershäuser, W. (Darmstadt, Tech. Hochsch.) ; Papuga, J. (KU Leuven, Dept. Phys. Astron.) ; Sánchez, R. (Darmstadt, GSI) ; Yordanov, D.T. (Orsay, IPN)
Publication	2016-05-05
Imprint	12 Apr 2016
Number of pages	6
Note	5 pages, 4 figures, 1 table, Accepeted by Phys. Rev. Lett. (2016)
In:	Phys. Rev. Lett. Phys. Rev. Lett.
DOI	10.1103/PhysRevLett.116.182502 10.1103/PhysRevLett.116.219901 (Addendum)
Subject category	nucl-th ; nucl-ex ; Nuclear Physics - Experiment ; Nuclear Physics - Theory
Accelerator/Facility, Experiment	CERN ISOLDE
Abstract	Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were 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 $\mu$ ($^{79}$Zn) = $-$1.1866(10) $\mu_{\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\nu g_{9/2}^{-1}$ shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment $\mu$ ($^{79m}$Zn) = $-$1.0180(12) $\mu_{\rm{N}}$ 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: $\delta \langle r^{2}_{c}\rangle^{79,79m}$ = +0.204(6) fm$^{2}$, providing first evidence of shape coexistence.
Copyright/License	arXiv nonexclusive-distrib. 1.0 publication: © 2016-2025 The Author(s) (License: CC-BY-3.0)

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