Study of isobaric analogue resonances in⁶⁵Cu by proton scattering from⁶⁴Ni

Abstract

Excitation functions of the elastic proton scattering by⁶⁴Ni were measured in the energy rangeE _p =5.0–6.2 MeV at 90°, 125° and 141° and in the energy intervals 5.00–5.25 MeV and 5.85–6.20 MeV at 110° and 160°. At 90° the excitation function of the inelastic proton scattering leading to the 2⁺(1.34 MeV) state in⁶⁴Ni was measured too. Out of the ten resonances found in the whole energy range, the resonances at 5.105, 5.985, 6.042 and 5.35 MeV were studied in more detail. The analysis of the elastic scattering provided the energy, orbital momentum, total and partial widths of the first three resonances. The inelastic scattering cross section for the last three resonances was sufficient to permit the spin determination by (p, p′ γ) angular correlations in the Goldfarb-Seyler geometry. The spectroscopic factorsS _pp are in good agreement with those obtained from (d, p) experiments. The resonance at 5.35 MeV exhibits an important 2p ⊗2 ⁺₁ amplitude in its wave function. Its inelastic partial widths and the corresponding spectroscopic factorsS _pp′ , were determined. The nonresonant background in the elastic channel is well described by shape and compound elastic scattering calculations with Perey's optical model parameters.