Quark momentum-space charge distribution in deuteron and neutron/proton structure functions ratio

The aim of the present article is to extract the free neutron structure function, which is experimentally unknown, form proton and deuteron deep inelastic scattering (DIS) data in the deep valence region. We begin by using the quark-exchange formalism, deuteron wave function and Fermi motion effect to investigate the deep inelastic electron scattering from the deuteron. The up- and down-quark momentum-space charge distribution in the deuteron is calculated and compared with those of tritium and helium 3. Then the free neutron structure function is evaluated such that we could get the best fit to the experimental NMC and SLAC data of proton and deuteron structure functions. Finally, it is shown that the ratio of free neutron to proton structure functions is in good agreement with the prediction of other theoretical models as well as the present available experimental data, which has been extracted from proton and deuteron cross-sections via Fermi smearing and density models.