High-resolution (e,e') study of isovector M1 and M2 transitions in the oxygen isotopes. Pt. 2

In a high-resolution electron scattering experiment, six isospin T = 3/2 levels in the excitation energy region of 11-15.3 MeV were populated in 17O. Five transitions at Esub(x) = 11.08, 12.47, 12.99, 14.23 and 14.75 MeV are predominantly of M2 nature with transition strengths B(M2, k)up = 6.1 +- 1.9, 6 +- 3, 6 +- 3, 46 +- 7 and 27 +- 9 μ2sub(N) x fm2, respectively. The transition to the 15.10 MeV level is mainly M1 with B(M1, k)up = 0.14 +- 0.04 μ2sub(N). For this level, a tentative spin-parity assignment of Jsup(π) = 3/2+ is possible. Also, a spin assignment of Jsup(π) = 9/2- is preferred for the 14.75 MeV level. The comparison of the transition strength to the level at 11.08 MeV with the prediction from the analogous unique first-forbidden β- decay of the 17N ground state indicates that it may be important to include psub(3/2)-hole configurations in the ground-state wave function of 17O. A tudinal component for the 14.23 MeV transition and assuming that the 12.99 MeV transition is pure E1, shows that mirror asymmetries in the mass 17 pair may be of non-zero magnitudes. (orig.)