Resonant parameters ($J^{\pi }$,$E_{\alpha }$,Γ,${\Gamma }_{\alpha }$/Γ) for 67 natural-parity levels in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ result from the analysis of new high-resolution ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$(α,${\alpha }_0$${)\mathrm{}}^{16}$O data. Accurate absolute differential cross sections were measured simultaneously at 19 angles for alphas scattered by thin ${\mathrm{O}}_2$ gas targets in a differentially-pumped scattering chamber. High resolution beams and small energy steps (Δ$E_{\alpha }$∼5 keV) permitted observation of narrow resonances in the range 9.2<$E_{\alpha }$<13.5 MeV (12.0<$E_x$<15.5 MeV). In addition, near $E_{\alpha }$=9.6 MeV ($E_x$=12.44 MeV), a pair detector measured the total cross section to the $0^{+}$ state in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ at 6.05 MeV. The pair data confirm a previously observed state at $E_x$=12.44 MeV but elastic scattering data imply &/Γ=62±15% for a $J^{\pi }$${=0\mathrm{}}^{+}$ level, in disagreement with the 13±2% reported by Garman et al.

• Received 26 October 1984

DOI:https://doi.org/10.1103/PhysRevC.31.717