Precision Mass Measurements of 58, 63Cr: Nuclear Collectivity Towards the N=40 Island of Inversion

Precision masses of ⁵⁸Cr and ⁶³Cr that track how collectivity grows toward the N=40 island of inversion, where expected shell closures melt into deformation.

ISOLTRAP mass spectrometry of neutron-rich chromium beams from ISOLDE, read as two-neutron separation energies and compared with shell-evolution expectations around N=40.

The island of inversion is one of the clearest places where the textbook magic numbers fail. These chromium masses are the experimental foothold on that shoreline from the ISOLTRAP chromium programme.