1. Charge radii of exotic potassium isotopes challenge nuclear theory and the magic character of N = 32
- Author
-
Gustav R. Jansen, C. M. Ricketts, Paul-Gerhard Reinhard, S. J. Novario, Shane Wilkins, Fredrik Gustafsson, Á. Koszorús, C. L. Binnersley, Mark Bissell, Witold Nazarewicz, Markus Kortelainen, A. R. Vernon, W. G. Jiang, B. S. Cooper, Gerda Neyens, S. W. Bai, Gaute Hagen, Andreas Ekström, A. Kanellakopoulos, Christian Forssén, R. P. de Groote, B. K. Sahoo, Thomas Papenbrock, Kieran Flanagan, Thomas Elias Cocolios, J. Billowes, R. F. Garcia Ruiz, Xiaofei Yang, S. Franchoo, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Helsinki Institute of Physics
- Subjects
kalium ,Nuclear Theory ,[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] ,nucl-th ,Atomic Physics (physics.atom-ph) ,Other Fields of Physics ,FOS: Physical sciences ,General Physics and Astronomy ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,nucl-ex ,114 Physical sciences ,physics.atom-ph ,01 natural sciences ,Effective nuclear charge ,Physics - Atomic Physics ,Nuclear Theory (nucl-th) ,Nuclear physics ,Charge radius ,0103 physical sciences ,Nuclear Physics - Experiment ,Neutron ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics ,Physics ,isotoopit ,010308 nuclear & particles physics ,Charge (physics) ,Nuclear matter ,[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph] ,Coupled cluster ,Isotopes of potassium ,Nuclear Physics - Theory ,ydinfysiikka ,Nuclear density - Abstract
Nuclear charge radii are sensitive probes of different aspects of the nucleon-nucleon interaction and the bulk properties of nuclear matter; thus, they provide a stringent test and challenge for nuclear theory. The calcium region has been of particular interest, as experimental evidence has suggested a new magic number at $N = 32$ [1-3], while the unexpectedly large increases in the charge radii [4,5] open new questions about the evolution of nuclear size in neutron-rich systems. By combining the collinear resonance ionization spectroscopy method with $\beta$-decay detection, we were able to extend the charge radii measurement of potassium ($Z =19$) isotopes up to the exotic $^{52}$K ($t_{1/2}$ = 110 ms), produced in minute quantities. Our work provides the first charge radii measurement beyond $N = 32$ in the region, revealing no signature of the magic character at this neutron number. The results are interpreted with two state-of-the-art nuclear theories. For the first time, a long sequence of isotopes could be calculated with coupled-cluster calculations based on newly developed nuclear interactions. The strong increase in the charge radii beyond $N = 28$ is not well captured by these calculations, but is well reproduced by Fayans nuclear density functional theory, which, however, overestimates the odd-even staggering effect. These findings highlight our limited understanding on the nuclear size of neutron-rich systems, and expose pressing problems that are present in some of the best current models of nuclear theory., Comment: submitted version; revision accepted in Nature Physics
- Published
- 2021
- Full Text
- View/download PDF