Mirror symmetry at high spin in 51Fe and 51Mn -: art. no. 051303

Gamma decays from excited states in the T-z= -1/2 nucleus Fe-51 have been observed for the first time. The differences in excitation energies as compared with those of the mirror partner, Mn-51, have been interpreted in terms of Coulomb effects and the resulting Coulomb energy differences (CED) can be understood intuitively in terms of particle-alignment effects. A new CED effect has been observed, in which different CED trends have been measured for each signature of the rotational structures that characterize these mind-f(7/2) shell nuclei. Large-scale fp-shell model calculations have been used to compute the trends of the CED as a function of spin. The result of comparing these calculations with the data demonstrates an ability to reproduce the fine details of the Coulomb effects with a precision far greater than has been previously achieved.