R.S. Hicks

High momentum transfer longitudinal and transverse form factors of the 7Li ground-state doublet

Abstract Longitudinal and transverse electromagnetic form factors of the 7Li ground-state doublet (the J π = 3 2 − ground state and the E x =478 keV , J π = 1 2 − first excited state) were measured by electron scattering up to momentum transfers of 4.2 and 4.5 fm−1, respectively. The transverse form factors show no diffraction structures in the high momentum transfer region which could be unambiguously identified as signatures of meson-exchange currents; however, they lie above existing calculations which do not include such contributions. The longitudinal elastic form factor has a second maximum as does the C2 form factor of the first excited state.

Comparison of isoscalar and isovector (e, e′) M1 form factors at high momentum transfer

Abstract Electron scattering M1 form factors have been measured for the ground state and for the 2.313 MeV M1 transition in 14 N. Whereas the ground-state form factor is in good accord with 1p-shell models, the data for the 2.313 MeV transition show an unexplained enhancement at high momentum transfers.

The low lying levels of 7Li studied by electron scattering

Abstract The M1 and M3 form factors of the 7 Li J π = 3 2 − ground state and the M1 and E2 form factors of the J π = 1 2 − , 478 keV first excited state were measured by 180° electron scattering. There is good agreement between the data and calculations using the Cohen and the Kurath shell model amplitudes. The harmonic oscillator parameter consistent with the data is b = 1.65 fm.

Multi-nucleon degrees of freedom in inelastic form factors of 7Li

Abstract The electromagnetic form factors of the 4.63 MeV excitation ( J π = 7 2 - ) in 7Li were measured over the momentum transfer range 0.8⩽q⩽4.2 fm−1. Comparison to the form factors of the ground-state doublet indicates that high multipoles, not allowed within the 1p shell, may make significant contributions to the transverse form factors but not in the longitudinal ones. These contributions are much larger than those predicted by a 2 h ω calculation. The presence of multi-nucleon current-like contributions in the transition is suggested.