Isomer Shift and Magnetic Moment of the Long-Lived 1/2$^+$ Isomer in $^{79}_{30}$Zn$_{49}$: Signature of Shape Coexistence near $^{78}$Ni
Isomer Shift and Magnetic Moment of the Long-Lived 1/2$^+$ Isomer in $^{79}_{30}$Zn$_{49}$: Signature of Shape Coexistence near $^{78}$Ni
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DOI：
10.1103/physrevlett.116.219901
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发表时间：
2016-04
影响因子：
8.6
通讯作者：
X. Yang;C. Wraith;L. Xie;C. Babcock;J. Billowes;M. Bissell;K. Blaum;B. Cheal;K. Flanagan;R. Ruiz;W. Gins;C. Gorges;L. K. Grob;H. Heylen;S. Kaufmann;M. Kowalska;J. Kraemer;S. Malbrunot-Ettenauer;R. Neugart;G. Neyens;W. Nörtershäuser;J. Papuga;R. Sánchez;D. Yordanov
中科院分区：
文献类型：
--
作者：
X. Yang;C. Wraith;L. Xie;C. Babcock;J. Billowes;M. Bissell;K. Blaum;B. Cheal;K. Flanagan;R. Ruiz;W. Gins;C. Gorges;L. K. Grob;H. Heylen;S. Kaufmann;M. Kowalska;J. Kraemer;S. Malbrunot-Ettenauer;R. Neugart;G. Neyens;W. Nörtershäuser;J. Papuga;R. Sánchez;D. Yordanov
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.
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.