Neutron-Hole-State Structure inN=81Nuclei. I.Sm144andNd142(p,d)

Angular distributions of deuterons from the ($p,d$) reaction (energy resolution ∼35 keV) on ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$ and ${}_{}{}^{142}{}_{}{}^{}\mathrm{Nd}$ at $E_p=35\mathrm{}$ MeV have been measured and compared with distorted-wave Born-approximation (DWBA) calculations. The DWBA calculations were performed both with and without the finite-range and nonlocality corrections. In some typical cases corrections were also included for the nuclear density dependence of the effective $\mathrm{pn}$ interaction. The DWBA cross sections for $l=5\mathrm{}$ show an enhanced sensitivity to the inclusion of these corrections. Calculations including both the nonlocality and finite-range corrections yield acceptable spectroscopic factors. Considerable fractionation of the $\left(2\mathrm{}{d}_{\frac{5}{2}}\right)_{\nu }^{}{}_{}{}^{-1\mathrm{}}$ and the $\left(1\mathrm{}{g}_{\frac{7}{2}}\right)_{\nu }^{}{}_{}{}^{-1\mathrm{}}$ states is observed. No measurable population of neutron states in the $82<N\le 126$ major shell was observed. The single-neutron-hole energies (in MeV) are as follows: $d_{\frac{3}{2}}$, 0.0; $s_{\frac{1}{2}}$, 0.45; $h_{\frac{11}{2}}$, 1.22; $d_{\frac{5}{2}}$, 1.52; and $g_{\frac{7}{2}}$, 2.12 for ${}_{}{}^{143}{}_{}{}^{}\mathrm{Sm}$; and $d_{\frac{3}{2}}$, 0.0; $s_{\frac{1}{2}}$, 0.43; $h_{\frac{11}{2}}$, 1.07; $d_{\frac{5}{2}}$, 1.47; and $g_{\frac{7}{2}}$, 2.20 for ${}_{}{}^{141}{}_{}{}^{}\mathrm{Nd}$. Data on the systematics of splitting and movement of these single-neutron-hole states as a function of the proton number ($Z$) in ${}_{}{}^{143}{}_{}{}^{}\mathrm{Sm}$, ${}_{}{}^{141}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{139}{}_{}{}^{}\mathrm{Ce}$, and ${}_{}{}^{137}{}_{}{}^{}\mathrm{Ba}$ shall be presented in a subsequent paper.