Charge radii of exotic potassium isotopes challenge nuclear theory and the magic character of N = 32
Artikel i vetenskaplig tidskrift, 2021

Nuclear charge radii are sensitive probes of different aspects of the nucleon–nucleon interaction and the bulk properties of nuclear matter, providing a stringent test and challenge for nuclear theory. Experimental evidence suggested a new magic neutron number at N = 32 (refs. 1–3) in the calcium region, whereas the unexpectedly large increases in the charge radii4,5 open new questions about the evolution of nuclear size in neutron-rich systems. By combining the collinear resonance ionization spectroscopy method with β-decay detection, we were able to extend charge radii measurements of potassium isotopes beyond N = 32. Here we provide a charge radius measurement of 52K. It does not show a signature of magic behaviour at N = 32 in potassium. The results are interpreted with two state-of-the-art nuclear theories. The coupled cluster theory reproduces the odd–even variations in charge radii but not the notable increase beyond N = 28. This rise is well captured by Fayans nuclear density functional theory, which, however, overestimates the odd–even staggering effect in charge radii. These findings highlight our limited understanding of the nuclear size of neutron-rich systems, and expose problems that are present in some of the best current models of nuclear theory.

Författare

Agota Koszorús

University of Liverpool

KU Leuven

X. F. Yang

KU Leuven

Beijing University of Technology

Weiguang Jiang

Oak Ridge National Laboratory

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

University of Tennessee

S. J. Novario

University of Tennessee

Oak Ridge National Laboratory

S. W. Bai

Beijing University of Technology

J. Billowes

University of Manchester

C. L. Binnersley

University of Manchester

M. L. Bissell

University of Manchester

T. E. Cocolios

KU Leuven

B. S. Cooper

University of Manchester

R. P. de Groote

Jyväskylän Yliopisto

Helsingin Yliopisto

Andreas Ekström

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

K. T. Flanagan

University of Manchester

Christian Forssén

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

S. Franchoo

Institut de Physique Nucleaire Orsay

R. F.Garcia Ruiz

Massachusetts Institute of Technology (MIT)

CERN

F. P. Gustafsson

KU Leuven

G. Hagen

Oak Ridge National Laboratory

G. R. Jansen

Oak Ridge National Laboratory

A. Kanellakopoulos

KU Leuven

M. Kortelainen

Helsingin Yliopisto

Jyväskylän Yliopisto

W. Nazarewicz

Michigan State University

G. Neyens

CERN

KU Leuven

T. Papenbrock

University of Tennessee

Oak Ridge National Laboratory

P. G. Reinhard

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

C. M. Ricketts

University of Manchester

B. K. Sahoo

Physical Research Laboratory

A. R. Vernon

University of Manchester

KU Leuven

S. G. Wilkins

CERN

Nature Physics

1745-2473 (ISSN)

Vol. In Press

Ämneskategorier

Subatomär fysik

Atom- och molekylfysik och optik

Annan fysik

DOI

10.1038/s41567-020-01136-5

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Senast uppdaterat

2021-03-03