Leakage and overlap of the partons inside nucleon and the nuclear effect on the nucleon structure function

In the nuclear medium, there are the non-nucleonic components. The leak-out partons, which form some colour-singlet parton clusters, are the origion of the non-nucleonic components. Meanwhile, the small x partons become co-used by several nucleons because the partons' longitudinal size extends over more than one nucleon. The nucleon effective mass can be successfully used as the only free parameter to adjust the structure function ratios recently measured by NMC.