Dustin Scriven
(Facility for Rare Isotope Beams)
In this work, the new observation of an isomer in $^{73}$Co is reported. The $T_{1/2}=202(20)\ \mu\textnormal{s}$ isomer at 1178 keV was observed using the FRIB Decay Station initiator (FDSi) at the Facility for Rare Isotope Beams (FRIB). This isomer is driven by a $1/2^-$ deformed 1p-2h proton intruder state, and has analogous configurations in lower-mass Co isotopes. In $^{69}$Co, the deformed isomer is energetically near the spherical g.s. Several state-of-the-art shell-model calculations predict inversion of this isomer with the g.s. in the $N=40-50$ region. The new observation at 1178 keV indicates an increase in the energy away from inversion. Here, complementary calculations are compared with the new observation in mind, exposing challenges in predicting inversion in the $N=40-50$ region. The presented results suggest there is no island of shape inversion from this proton-driven intruder state in the cobalt isotopes approaching $N=50$.
Dustin Scriven
(Facility for Rare Isotope Beams)
Alex Brown
(Facility for Rare Isotope Beams)
Amelia Doetsch
(Facility for Rare Isotope Beams)
Andrew Stuchbery
(Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University)
Artemis Spyrou
(Facility for Rare Isotope Beams)
Artemis Tsantiri
(Facility for Rare Isotope Beams)
Ben Crider
(Department of Physics and Astronomy, Mississippi State University)
Brad Sherrill
(Facility for Rare Isotope Beams)
Brendon Longfellow
(Lawrence Livermore National Laboratory)
Brooks Olree
(Department of Physics and Astronomy, Mississippi State University)
Daniel Ayangeakaa
(Department of Physics and Astronomy, University of North Carolina at Chapel Hill)
Darek Seweryniak
(Physics Division, Argonne National Laboratory)
Duc Dao
(Universit´e de Strasbourg)
Eleanor Ronning
(Facility for Rare Isotope Beams)
Frederic Nowacki
(Universit´e de Strasbourg)
Heather Crawford
(Nuclear Science Division, Lawrence Berkeley National Laboratory)
Hershini Gadaria
(Facility for Rare Isotope Beams)
James Huffman
(Facility for Rare Isotope Beams)
Jason Holt
(TRIUMF)
Jessica Berkman
(Facility for Rare Isotope Beams)
Konstantinos Bosmpotinis
(Facility for Rare Isotope Beams)
Mejdi Mogannam
(Facility for Rare Isotope Beams)
Mitch Allmond
(Physics Division, Oak Ridge National Laboratory)
Oleg Tarasov
(Facility for Rare Isotope Beams)
Rebeka Lubna
(Facility for Rare Isotope Beams)
Robert Grzywacz
(Department of Physics and Astronomy, University of Tennessee, Knoxville)
Robert Janssens
(Department of Physics and Astronomy, University of North Carolina at Chapel Hill)
Samuel Ajayi
(Department of Physics, Florida State University)
Sean Liddick
(Facility for Rare Isotope Beams)
Shane Watters
(Facility for Rare Isotope Beams)
Sydney Coil
(Facility for Rare Isotope Beams)
Takayuki Miyagi
(Center for Computational Sciences, University of Tsukuba)
Tawfik Gaballah
(Facility for Rare Isotope Beams)
Thomas Ruland
(Physics Division, Oak Ridge National Laboratory)
Tim Gray
(Department of Physics and Astronomy, University of Tennessee, Knoxville)
Timilehin Ogunbeku
(Lawrence Livermore National Laboratory)
Toby King
(Physics Division, Oak Ridge National Laboratory)
Zhengyu Xu
(Department of Physics and Astronomy, University of Tennessee, Knoxville)