Speaker
Mr
Maxime Mougeot
(CNRS, Universite Paris Sud, Orsay)
Description
As first hinted at in the mid-seventies by pioneering on-line mass measurements of neutron-rich Na isotopes, the spherical shell, or sub-shell, gaps described within the shell model of the atomic nucleus are prone to rapid evolution with proton and neutron number. Far from being isolated, the region of shell erosion around N=20 is actually part of a larger “archipelago of islands of inversion”. One such island, around N=40, is thought to exhibit maximum quadrupole deformation for 64Cr. However, the mass surface in the chromium chain, approaching N=40, remains too imprecisely known. Over the last thirty-years, on-line Penning-trap mass spectrometry associated with the “ISOL” production technique has proven to be a particularly successful tandem for the precise determination of the mass of exotic species. Although chromium was not considered to be a traditional thick-target “ISOL” element, successful laser-ionization developments[1] combined with highly sensitive mass spectrometry techniques enabled the mass measurements of 52-63Cr, during two recent experimental campaigns at the ISOLDE facility, using the Penning-trap mass spectrometer ISOLTRAP[2]. The mass values obtained are of greatly refined precision thus shining new light on the development of ground-state collectivity towards N=40 in the chromium chain. Very recently, an ab-initio method, rooted in the IM-SRG framework, has been developed enabling the derivation of shell-model Hamiltonians from first principles thus extending the reach of ab-initio calculations to mid-shell nuclei[3]. A comparison of these state-of-the-art shell model calculations with our results will be presented.
References:
[1] Goodacre et al., Spect. Chimica Acta B, In Press (2017).
[2] Mukherjee et al., Eur. Phys. J. A 35, 1-29 (2008).
[3] Stroberg et al., Phys. Rev. Lett. 118, 032502 (2017).
Primary author
Mr
Maxime Mougeot
(CNRS, Universite Paris Sud, Orsay)
Co-authors
Prof.
Achim SCHWENK
(Technische Universität Darmstadt)
Mr
Andree WELKER
(Technische Universität Dresden)
Dr
Bruce Marsh
(CERN)
Dr
Christoph SEIFFERT
(CERN)
Dr
David Lunney
(CNRS, Universite de Paris Sud, Orsay)
Dr
Dennis NEIDHERR
(GSI Helmholtzzentrum für Schwerionenforschung)
Dr
Dinko Atanasov
(Max-Planck Institute for Nuclear Physics)
Dr
Dmitry FEDOROV
(Petersburg Nuclear Physics Institute, Gatchina, Russia)
Dr
Frank Herfurth
(GSI Helmholtzzentrum für Schwerionenforschung)
Mr
Frank WIENHOLTZ
(CERN)
Dr
Jason Holt
(TRIUMF)
Mr
Johannes SIMONIS
(Technische Universität Darmstadt)
Prof.
Kai ZUBER
(Technische Universität Dresden)
Mrs
Katerina CHRYSALIDIS
(CERN)
Prof.
Klaus BLAUM
(Max-Planck Institute for Nuclear Physics)
Prof.
Lutz SCHWEIKHARD
(Ernst-Moritz-Arndt-Universität, Greisswald)
Dr
Marco Rosenbusch
(RIKEN Nishina Center for Accelerator-based Science)
Dr
Ragnar STROBERG
(TRIUMPH)
Dr
Robert Wolf
(Max-Planck-Institut für Kernphysik)
Dr
Sebastian GEORGE
(Max-Planck Institute for Nuclear Physics)
Dr
Sebastian Rothe
(CERN, Geneva, Switzerland)
Dr
Thomas Day Goodacre
(CERN)
Dr
Valentin FEDOSEEV
(CERN)
Dr
Vladimir Manea
(CERN, Geneva, Switzerland)