Abstract

Nuclear effects due to the presence of spin-1 isosinglet 6-quark clusters in the deuteron on the extraction of both spin-independent and spin-dependent neutron structure functions are investigated. The cursive Greek chi-dependences of the 6-quark cluster structure functions are estimated by using a perturbative QCD (pQCD) dimensional counting rules. Within this framework, the ratio of the deuteron structure function to the free nucleon structure function can be well described. We find that the nuclear effect on the extracted spin-dependent neutron structure function is very different from that on the spin-independent neutron structure function. The effect enhances the Bjorken sum by about 10%, whereas it decreases the Gottfried sum by about 7%. The formalism for calculating nuclear effects is further used to evaluate the spin-dependent structure function of the 3He nucleus and a good self-consistent check is obtained.