Nuclear Effects on the Extraction of Neutron Structure Functions

Nuclear effects in light nuclei due to the presence of spin-one isosinglet 6-quark clusters are investigated. The quark distributions of 6-quark clusters are obtained by using a perturbative QCD (pQCD) based framework, which allows us to get a good description of the ratio of the deuteron structure function to the free nucleon structure function. Nuclear effects on the extraction of the neutron structure functions $F_2^n$ and $g_1^n$ are estimated. We find that the 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 its correction to the Gottfried sum is rather small. The formalism for calculating nuclear effects is further used to evaluate the spin-dependent structure function of the $^3$He nucleus and a good self-consistent check is obtained.