Competition between normal and intruder states inside the "island of inversion"
Tripathi, Vandana × Tabor, S. L Mantica, P. F Utsuno, Y Bender, P Cook, J Hoffman, C. R Lee, Sangjin Otsuka, Taka Pereira, J Perry, M Pepper, K Pinter, J. S Stoker, J Volya, A Weisshaar, D #
Published for the American Physical Society by the American Institute of Physics
Physical Review C, Nuclear Physics vol:76 issue:2
decay of the exotic
20) is reported. For the first time, the low-energy level structure
4), is obtained from
spectroscopy using fragment-
The level structure clearly displays “inversion,” i.e., intruder states with mainly 2
the normal states to higher excitation energies. The good agreement in excitation energies and the weak and
electromagnetic decay patterns with Monte Carlo shell model calculations with the SDPF-M interaction in the
valence space confirms the small
shell gap. The relative position of the
excited states provides valuable information to understand better the
20 shell gap.