15N( [formula omitted], po) 15N and the levels of 16O for Ex = 14.8–18.6 MeV

Abstract

Angular distributions of cross section and analyzing power for elastic scattering of protons from 15N have been measured for E p = 2.7–7.0 MeV. A phase-shift analysis of the data yields spin-parity assignments and level parameters for seventeen states of 16O in the excitation energy region 14.8–18.6MeV. Three of the resonances have not previously been identified, among them being a broad J π = 2 − level at E p = 6.1 MeV which is almost certainly the analog of the 2 − 1p1h state with configuration ( d 3 2 , p 1 2 −1 ) at E x ∽ 5.0 MeV in 16N. The broad level previously reported near E p = 5.0 MeV has been observed and its parameters determined. A resonance analysis of the phase shifts yielded values of E r , Γ and Γ p for all of the levels. The J π assignments are in agreement with previously reported values. For resonances having J = l, the data can usually be fit with a resonant phase shift corresponding to either J = l + 1 or J = l − 1, in addition to the phase shift for J = l. Which of the two spurious- J solutions occurs seems to depend on whether the partial wave through which the resonant state is formed is J = l + 1 2 or J = l − 1 2 .