No abstract

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G n E /G n M , obtained via recoil polarimetry from the quasielastic 2 H( e, e ′ n) 1 H reaction at Q 2 values of 0.45, 1.13, and 1.45 (GeV/c) 2 with relative statistical uncertainties of 7.6 and 8.4% at the two higher Q 2 points, which were not reached previously via polarization measurements. Scale and systematic uncertainties are small.

at excitation energies between 1S and 23 MeV. Measurements were performed at 90' for momentum transfers of 1.4, 1.S, 1.7, and 1.9 fm ' and at 160' for a momentum transfer of 1.7 fm '. Several prominent narrow peaks were observed in the spectra of both nuclei. The measured form factors for levels in '~O at 1S.78, 17.06, 20.14, and 20.70 MeV and in "0 at 18.70, 20.36, and 22.39 MeV are, within experimental uncertainties, completely transverse. These strongly excited states are assumed to arise from isovector M4 transitions of the type 1@3&2~1d5q2. A simple weak-coup1ing model is used to assign spins to the levels in ' O. Finally, we also report measurements for several narrow states in both nuclei, for which the spins and parities have not yet been identified.

Form-factor measurements in the momentum-transfer range 0.6~q~2. 7 fm ' are presented for the 1 levels in ' 0 at 4.46, 6.20, 7.62, and 8.04 MeV, the 3 levels at 5.10, 6.40, and 8.29 MeV, and the 5 levels at 7.86 and 8.13 MeV. These are the first measurements of the 5 states by inelastic scattering and the first electron-scattering measurements of the higher 1 and 3 states. A Rosenbluth separation of the longitudinal and transverse form factors was performed by fitting the data with a phenomenological polynomial-times-Gaussian parametrization motivated by the form of theoretical form factors when harmonic-oscillator wave functions are used. Comparisons are made with structure models. The Coulomb form factors of several levels indicate the significance of small admixtures of 3Am components in the negative-parity wave functions.