Longitudinal electron scattering response functions of 3H and 3He -: art. no. 044001

Trinucleon longitudinal response functions R-L(q,omega) are calculated for q values up to 500 MeV/c. These are the first calculations beyond the threshold region in which both three-nucleon (3N) and Coulomb forces are fully included. We employ two realistic NN potentials (configuration space BonnA, AV18) and two 3N potentials (UrbanaIX, Tucson-Melborne). Complete final state interactions are taken into account via the Lorentz integral transform technique. We study relativistic corrections arising from first-order corrections to the nuclear charge operator. In addition the reference frame dependence due to our nonrelativistic framework is investigated. For qless than or equal to350 MeV/c we find that 3N forces give effects of between 5 % and 10% in the peak region and of 15 % in the threshold region at the lowest considered momentum transfer (q=174 MeV/c), while the dependence on other theoretical ingredients is small. At qgreater than or equal to400 MeV/c relativistic corrections to the charge operator and effects of frame dependence, especially for large omega, become more important. In comparison with experimental data there is generally a rather good agreement. Exceptions are the responses at excitation energies close to threshold, where there exists a large discrepancy with experiment at higher q. In the He-3 case one finds a much improved agreement with experiment both in the peak region and in the low- q-low- omega region if 3N forces are included. However in comparison with the existing data for H-3 the inclusion of 3N forces appears to have the opposite effect in the peak region.