De-excitation of the strongly coupled band in $^{177}$Au and implications for core intruder configurations in the light Hg isotopes

M. Venhart , F.A. Ali , W. Ryssens , J.L. Wood , D.T. Joss , A.N. Andreyev , K. Auranen , B. Bally (1) , M. Balogh , M. Bender (2, 3) , R.J. Carroll , J.L. Easton , P.T. Greenlees , T. Grahn , P.H. Heenen , A. Herzáň , U. Jakobsson , R. Julin , S. Juutinen , D. Kĺč , J. Konki , E. Lawrie , M. Leino , V. Matoušek , C.G. Mcpeake , D. O'Donnell , R.D. Page , J. Pakarinen , J. Partanen , P. Peura , P. Rahkila , P. Ruotsalainen , M. Sandzelius , J. Sarén , B. Sayği , M. Sedlák , C. Scholey , J. Sorri , S. Stolze , A. Thornthwaite , J. Uusitalo , M. Veselský

1 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
2 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
3 IPNL - Institut de Physique Nucléaire de Lyon

Excited states in the proton-unbound nuclide $^{177}$Au were populated in the $^92}$Mo($^{88}$Sr, p2n) reaction and identified using the Jurogam-II and GREAT spectrometers in conjunction with the RITU gas-filled separator at the University of Jyväskylä Accelerator Laboratory. A strongly coupled band and its decay path to the 11/2−α-decaying isomer have been identified using recoil-decay tagging. Comparisons with cranked Hartree-Fock-Bogoliubov (HFB) calculations based on Skyrme energy functionals suggest that the band has a prolate deformation and is based upon coupling the odd 1h11/2 proton hole to the excited 02+ configuration in the $^{178}$Hg core. Although these configurations might be expected to follow the parabolic trend of core Hg(02+) states as a function of neutron number, the electromagnetic decay paths from the strongly coupled band in $^{177}$Au are markedly different from those observed in the heavier isotopes above the midshell. This indicates that a significant change in the structure of the underlying A+1Hg core occurs below the neutron midshell.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

M. Venhart, F.A. Ali, W. Ryssens, J.L. Wood, D.T. Joss, et al.. De-excitation of the strongly coupled band in $^{177}$Au and implications for core intruder configurations in the light Hg isotopes. Phys.Rev.C, 2017, 95 (6), pp.061302. ⟨10.1103/PhysRevC.95.061302⟩. ⟨hal-01554898⟩