Proxy- symmetry in A=60-90 region
Applications of the proxy- model of Bonatsos and collaborators to nuclei in A=60-90 region introduces proxy- symmetry. Shell model spaces with single particle (sp) orbits , , and are essential for these nuclei and also protons and neutrons in this region occupy the same sp orbits. With this and applying the "proxy scheme", the changes to giving the SGA . With , we have the proxy- model. It is easy to see that proxy- symmetry implies goodness of the symmetry appearing above, i.e. proxy- symmetry. Shell model calculations pointing out the need for orbit, ground state masses, shape changes and shape co-existence in A=60-90 region and GT distributions clearly show the importance of proxy- in this mass region. Besides presenting this evidence, new proxy schemes with , and that are generated by good proxy- symmetry are described in some detail. An important feature is that the four proxy symmetries , , and appear twice.