An improved impulse approximation treatment of the 'allowed' weak and analogue electromagnetic transitions in 12C

Weak and electromagnetic transitions between the 12C ground state and 1+ members of the T = 1 isomultiplet are studied in the framework of the impulse approximation. Uncertainties due to the nuclear configuration mixing and radial effects are examined, the former in the framework of the Cohen-Kurath and Migdal models, and the latter in the density-dependent Hartree-Fock approach. Within the uncertainties of the models, the weak and electromagnetic observables at low momentum transfer (<= 0.5 fm-1) are reasonably well reproduced. The inelastic electron scattering form factor at higher momentum transfer shows strong deviations from the impulse approximation estimates. (Auth.)