Refined analysis on the parton distribution functions of the proton

We explore the application of a two-component model of proton structure functions in the analysis of deep-inelastic scattering (DIS) data at low Q ² and small x. This model incorporates both vector meson dominance and the correct photo-production limit. The CJ15 parameterization is applied to the QCD component, in order to take into account effects of order 1/Q ² effects, such as target mass corrections and higher twist (HT) contributions. The parameters of the leading twist parton distribution functions (PDFs) and HT coefficient functions are determined by fitting DIS data. The second moments of the PDFs are extracted and compared with other global fits and lattice determinations. (paper)