Investigation of the neutron structure function via semi-inclusive deep   inelastic electron scattering off the deuteron
  The production of slow nucleons in semi-inclusive deep inelastic electron scattering off the deuteron is investigated in the region $x \gsim 0.3$ for kinematical conditions accessible at $HERA$. Within the spectator mechanism the semi-inclusive cross section exhibits a scaling property, which can be used as a model-independent test of the dominance of the spectator mechanism itself, providing in this way an interesting tool to investigate the neutron structure function. The possibility of extracting model-independent information on the neutron to proton structure function ratio from semi-inclusive experiments is also illustrated. 
Silvano Simula (INFN - Sezione Sanita')