Excitation of M1 states in 58Ni and 60Ni by 65 MeV polarized proton inelastic scattering

Abstract

We studied the 1 + states in 58Ni and 60Ni by using the 58 Ni( p , p′) 58 Ni and 60 Ni( p , p′) 60 Ni reactions at 65 MeV with high resolution, in order to search for the fragmentation of the 1 + states at excitation energies of E x = 7–11 MeV. From the similarity in experimental shapes of both cross sections and analyzing powers for the well-known 1 + states and from comparison with microscopic DWBA calculations under the assumptions of pure (f 7 2 −1f 5 2 ) and ν(p 3 2 P 1 2 ) configurations, four states in 58Ni and one state in 60Ni have been identified as the candidates of the 1 + states of a (f 7 2 −1f 5 2 ) or ν(p 3 2 P 1 2 ) configuration in the M1 giant resonance region of E x = 7–10 MeV, though the strengths are very weak.