Elastic and inelastic scattering of 280 and 489 MeV protons from 58Ni

Nonrelativistic and relativistic collective deformed potential models have been used to study the excitation of seven states in 58Ni by 280 and 489 MeV unpolarized protons. Optical model potentials were determined at each energy by fitting elastic scattering data using both of the models. Deformation lengths were also obtained using both models with no dependence on incident energy observed for either model. The average value of the hadronic deformation lengths along with the charge deformation lengths were used to calculate neutron to proton multipole matrix elements (MnMp). Five transitions, 2+1, 1.45 MeV; 2+3, 3.04 MeV; 2+4, 3.26 MeV; 4+1, 2.46 MeV; and the 4+5, 4.75 MeV state were determined to be isoscalar, i.e. MnMp = NZ. The 4+2, 3.63 MeV state was observed to be a proton-like transition with MnMp = 0.43 ± 0.18. At small scattering angles, the relativistic model gave consistently larger cross sections than the nonrelativistic model. This effect was much larger at 280 MeV than at 489 MeV.