EFFECTIVE INTERACTIONS FOR A = 41-66 NUCLEI

A new two-body interaction is derived for nuclei in a large part of the 0f1p shell by fitting two-body matrix elements to 494 energy levels in A = 41-66 nuclei. For the shell-model basis a Ca-40 core and a model space consisting of 0f7/2n(1p(3/2)0f(5/2)1p1/2)m+0f7/2n-1(1p(3/2)0f(5/2)1p1/2)1+m configurations was assumed. By varying 40 linear combinations of matrix elements and fixing those that are not well-determined to values of a previously determined starting interaction, an r.m.s deviation between fitted and experimental energies of 193 keV has been achieved. An excellent reproduction of low-lying energy levels, and the magnetic dipole and electric quadrupole moments for the ground states as well as some excited states, is obtained with the new interaction. Further calculations with the new interaction also suggest that it is a valuable extension to the region of nuclei far from stability and to the mass regions currently of astrophysical interest.