Monopole Strength in Ni-58

Abstract

Differential cross-section data from 0-degrees to 8-degrees for inelastic scattering of 129 MeV alpha particles exciting Ni-58 in the region of 14-22 MeV have been analyzed to explore the existence of monopole strength at approximately E(x) = 17 MeV. The angular distribution for a peak at E(x) = 17.0 MeV with GAMMA = 4.0 MeV is consistent with an E0 transition exhausting 19 +/- 10% of the E0 energy-weighted sum rule (EWSR). The angular distributions for peaks at E(x) = 16.1 and 20.4 MeV with GAMMA = 4.7 and 4.4 MeV, respectively, were fit by 52 +/- 10% of the E2 EWSR and a combination of E2 (6.9 +/- 2.0 EWSR) and E0 (2.9(-2.9)+2.1% EWSR).