Investigating an island of inversion: Physicists pinpoint boundary where nuclear shell model breaks down

Scientists trace rare nuclei 'island' where physics rules break apart

Swiss researchers at CERN have mapped the edge of a rare nuclear island where conventional shell model rules no longer apply.

From CERN (CH) ISOLDE : “ISOLDE investigates island of inversion”

From CERN (CH) ISOLDE 2 September, 2025 Ana Lopes An experiment carried out at CERN’s ISOLDE facility has determined the "western shore" of a small island of atomic nuclei, where conventional nuclear rules break down. The atomic nucleus was discovered over a century ago, yet many questions remain about the force that keeps its constituent…

Investigating an island of inversion: Physicists pinpoint boundary where nuclear shell model breaks down

An experiment carried out at CERN's ISOLDE facility has determined the western shore of a small island of atomic nuclei, where conventional nuclear rules break down.

ISOLDE investigates island of inversion

The ISOLDE facility at CERN (Image: CERN) The atomic nucleus was discovered over a century ago, yet many questions remain about the force that keeps its constituent protons and neutrons together and the way in which these particles pack themselves together within it. In the classic nuclear shell model, protons and neutrons arrange themselves in shells of increasing energy, and completely filled outer shells of protons or neutrons result in parti…

$^{61}\mathrm{Cr}$ as a doorway to the $N=40$ island of inversion

Knowing the correct ground-state spin of neutron-rich nuclei is crucial for the interpretation of $\ensuremath{\beta}$-decay data and nuclear structure, but experimental information is often scarce. Using a novel laser excitation scheme specifically developed for this work the authors measured the ground-state spin and magnetic dipole moment of the short-lived nucleus ${}^{61}$Cr at ISOLDE-CERN with high-resolution resonance ionization laser spe…