Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States
Résumé
One-neutron knockout reactions have been performed on a beam of radioactive 53Co in a high-spin
isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic
nucleus with a significant cross section, and hence represents a technique that is applicable to the planned
new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections
among the excited states can be predicted to a high level of accuracy when reliable shell-model input is
available. The work has resulted in a new level scheme, up to the 11þ band-termination state, of the protonrich
nucleus 52Co (Z ¼ 27, N ¼ 25). This has in turn enabled a study of mirror energy differences in
the A ¼ 52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei.
The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the
experimental observations.