LOCATION OF SINGLE-PARTICLE LEVELS IN MEDIUM MASS NUCLEI

The levels of Ni/sup 59/, Ni/sup 61/, Fesup 57/, and Ti/sup 49/ are studied with (d,p) reactions. Angular distributions and absolute cross sections are analyzed with the aid of distorted-wave Born approximatlon calculations. Essentially all levels ln the Ni isotopes up to about I Mev binding energy are assigned to a shell-model state and their reduced widths are measured. From this, the center of gravity ' of each shell-model state is determined. The results are close to theoretical expectations. For example, the results explain the large energy gap between major shells, the energy of the 3s/sub 1/2/ state, and the semiclosed-shell behavior of 40 and 56 neutrons. The widths of the energy distributions of levels belonging to single shell-model states agree with the predictlons of the giant resonance theory, (auth)