Measurement of the F2n/F2p and d/u Ratios in Deep Inelastic Electron   Scattering off 3H and 3He
  We discuss a possible measurement of the ratio of the nucleon structure functions, F2n/F2p, and the ratio of the up to down quark distributions, u/d, at large x, by performing deep inelastic electron scattering from the 3H and 3He mirror nuclei with the 11 GeV upgraded beam of Jefferson Lab. The measurement is expected to be almost free of nuclear effects, which introduce a significant uncertainty in the extraction of these two ratios from deep inelastic scattering off the proton and deuteron. The results are expected to test perturbative and non-perturbative mechanisms of spin-flavor symmetry breaking in the nucleon, and constrain the structure function parameterizations needed for the interpretation of high energy e-p, p-p and p-pbar collider data. The precision of the expected data can also allow for testing competing parameterizations of the nuclear EMC effect and provide valuable constraints on models of its dynamical origin. 
G.G. Petratos, I.R. Afnan, F. Bissey, J. Gomez, A.T. Katramatou, W.   Melnitchouk and A.W. Thomas