Details

Autor(en) / Beteiligte

• Garcia Ruiz, R. F.
• Bissell, M. L.
• Blaum, K.
• Ekström, A.
• Frömmgen, N.
• Hagen, G.
• Hammen, M.
• Hebeler, K.
• Holt, J. D.
• Jansen, G. R.
• Kowalska, M.
• Kreim, K.
• Nazarewicz, W.
• Neugart, R.
• Neyens, G.
• Nörtershäuser, W.
• Papenbrock, T.
• Papuga, J.
• Schwenk, A.
• Simonis, J.
• Wendt, K. A.
• Yordanov, D. T.

Titel

Unexpectedly large charge radii of neutron-rich calcium isotopes

Ist Teil von

• Nature physics, 2016-06, Vol.12 (6), p.594-598

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain ‘magic’ numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly magic features are known in 40,48 Ca, and recently suggested in two radioactive isotopes, 52,54 Ca. Although many properties of experimentally known calcium isotopes have been successfully described by nuclear theory, it is still a challenge to predict the evolution of their charge radii. Here we present the first measurements of the charge radii of 49,51,52 Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theoretical calculations. The large and unexpected increase of the size of the neutron-rich calcium isotopes beyond N = 28 challenges the doubly magic nature of 52 Ca and opens new intriguing questions on the evolution of nuclear sizes away from stability, which are of importance for our understanding of neutron-rich atomic nuclei. Doubly magic atomic nuclei — having a magic number of both protons and neutrons — are very stable. Now, experiments revealing unexpectedly large charge radii for a series of Ca isotopes put the doubly magic nature of the 52 Ca nucleus into question.