Study of proton-hole states in 63Cu and 63Co. Pt. 1

This is the first part of an investigation on proton-hole states in 63Cu and 63Co, which were excited by 64Zn, 64Ni(d, 3He) reactions at an incident deuteron energy of Ed=52 MeV. Angular distribution measurements with polarized deuterons at moderate energy resolution (FWHM = 130 keV) have been complemented by a high-resolution study (FWHM = 20 keV) using an unpolarized beam. The combined data yield spin-parity assignments for hole states in 63Cu and 63Co up to excitation energies of 17 and 14 MeV, respectively. Strength distributions have been extracted in both nuclei up to Ex=20 MeV. The fragmentation of the strengths in 63Cu is distinctly different from that in 63Co but we observe similar spreading widths for the 7/2-, 3/2+, 1/2+ and 5/2+ strengths. The spreading widths of the 7/2- strengths in 63Cu and 63Co do not fit in a systematic energy dependence observed previously in the Zr region. Calculated ground-state occupancies and single-particle energies in 64Zn and 64Ni allowed the determination of Fermi surfaces. Systematic properties of the 2s1/2 proton single-particle energies were parametrized for all stable target nuclei in the mass region 16≤A≤66, Part (II) of the present study, an investigation on the γ-decay of the proton-hole states by the 64Zn, 64Ni(d, 3Heγ) reactions at Ed=31 MeV, will be presented in a forthcoming paper. (orig.)