Single-particle resonance levels in 14O examined by N13+p elastic resonance scattering

Single-particle properties of low-lying resonance levels in 14O have been studied efficiently by utilizing a technique of proton elastic resonance scattering with a 13N secondary beam and a thick proton target. The excitation functions for the N13+p elastic scattering were measured over a wide energy range of ECM=0.4-3.3MeV and fitted with an R-matrix calculation. A clear assignment of Jπ=2− has been made for the level at Ex=6.767(11)MeV in 14O for the first time. The excitation functions show a signature of a new 0− level at Ex=5.71(2)MeV with Γ=400(100)keV. The excitation energies and widths of the 14O levels are discussed in conjunction with the spectroscopic structure of A=14 nuclei with T=1.