title: Probing the N=32 Shell Closure below the Magic Proton Number Z=20: Mass Measurements of the Exotic Isotopes ^{52,53}K.
abstract: The recently confirmed neutron-shell closure at N=32 has been investigated for the first time below the magic proton number Z=20 with mass measurements of the exotic isotopes (52,53)K, the latter being the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N=32, slightly lower than for 52Ca, highlighting the doubly magic nature of this nuclide. Skyrme-Hartree-Fock-Bogoliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.
authors.affiliation: Institut für Physik, Ernst-Moritz-Arndt Universität Greifswald, 17487 Greifswald, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Rosenbusch
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Ascher
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Atanasov
authors.affiliation: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Barbieri
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Beck
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Blaum
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Borgmann
authors.affiliation: Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200d, B-3001 Heverlee, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Breitenfeldt
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.|Department of Physics, University of Istanbul, 34134 Istanbul, Turkey.
authors.forename: R B
authors.initials: RB
authors.lastname: Cakirli
authors.affiliation: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Cipollone
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: George
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Herfurth
authors.affiliation: CERN, 1211 Geneva 23, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Kowalska
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.|CERN, 1211 Geneva 23, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Kreim
authors.affiliation: CSNSM-IN2P3-CNRS, Université Paris-Sud, 91405 Orsay, France.
authors.forename: D
authors.initials: D
authors.lastname: Lunney
authors.affiliation: CSNSM-IN2P3-CNRS, Université Paris-Sud, 91405 Orsay, France.
authors.forename: V
authors.initials: V
authors.lastname: Manea
authors.affiliation: TRIUMF, 4004 Westbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Navrátil
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Neidherr
authors.affiliation: Institut für Physik, Ernst-Moritz-Arndt Universität Greifswald, 17487 Greifswald, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Schweikhard
authors.affiliation: CEA-Saclay, IRFU/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France.|Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany.|ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Somà
authors.affiliation: Institut für Kern- und Teilchenphysik, Technische Universität Dresden, 01069 Dresden, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Stanja
authors.affiliation: Institut für Physik, Ernst-Moritz-Arndt Universität Greifswald, 17487 Greifswald, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Wienholtz
authors.affiliation: Institut für Physik, Ernst-Moritz-Arndt Universität Greifswald, 17487 Greifswald, Germany.|Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: R N
authors.initials: RN
authors.lastname: Wolf
authors.affiliation: Institut für Kern- und Teilchenphysik, Technische Universität Dresden, 01069 Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Zuber