Surprising Charge-Radius Kink in the Sc Isotopes at N=20

Kristian König; Stephan Fritzsche; Gaute Hagen; Jason D Holt; Andrew Klose; Jeremy Lantis; Yuan Liu; Kei Minamisono; Takayuki Miyagi; Witold Nazarewicz; Thomas Papenbrock; Skyy V Pineda; Robert Powel; Paul-Gerhard Reinhard

doi:10.1103/PhysRevLett.131.102501

Surprising Charge-Radius Kink in the Sc Isotopes at N=20

Phys Rev Lett. 2023 Sep 8;131(10):102501. doi: 10.1103/PhysRevLett.131.102501.

Authors

Kristian König^{1

2}, Stephan Fritzsche^{3

4}, Gaute Hagen^{5

6}, Jason D Holt^{7

8}, Andrew Klose⁹, Jeremy Lantis^{1

10}, Yuan Liu¹, Kei Minamisono^{1

11}, Takayuki Miyagi^{2

12

13}, Witold Nazarewicz^{1

11}, Thomas Papenbrock^{6

14}, Skyy V Pineda^{1

10}, Robert Powel^{1

11}, Paul-Gerhard Reinhard¹⁵

Affiliations

¹ Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.
² Department of Nuclear Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany.
³ Helmholtz Institute Jena, 07743 Jena, Germany.
⁴ Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
⁵ Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
⁶ Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
⁷ TRIUMF, Vancouver, British Colombia, V6T 2A3, Canada.
⁸ Department of Physics, McGill University, Montréal, Quebec, H3A 2T8, Canada.
⁹ Department of Chemistry and Biochemistry, Augustana University, Sioux Falls, South Dakota 57197, USA.
¹⁰ Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
¹¹ Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
¹² ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
¹³ Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
¹⁴ Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
¹⁵ Friedrich-Alexander Universität, Erlangen 91058, Germany.

PMID: 37739365
DOI: 10.1103/PhysRevLett.131.102501

Abstract

Charge radii of neutron deficient ^{40}Sc and ^{41}Sc nuclei were determined using collinear laser spectroscopy. With the new data, the chain of Sc charge radii extends below the neutron magic number N=20 and shows a pronounced kink, generally taken as a signature of a shell closure, but one notably absent in the neighboring Ca, K, and Ar isotopic chains. Theoretical models that explain the trend at N=20 for the Ca isotopes cannot reproduce this puzzling behavior.