Towards parton distribution functions with theoretical uncertainties

Uncertainties of Parton Distribution Functions

High-energy particles interact through their quark and gluon constituents—the partons. By the asymptotic freedom of QCD, the parton cross sections may be approximated by perturbation theory. Then by the factorization theorem of QCD, the parton distribution functions of hadrons are the link between perturbative QCD and experimental measurements. This theory applies to a variety of high-energy pr...

Determination of polarized parton distribution functions and their uncertainties

We investigate the polarized parton distribution functions (PDFs) and their uncertainties by using the world data on the spin asymmetry A1. The uncertainties of the polarized PDFs are estimated by the Hessian method. The up and down valence-quark distributions are determined well. However, the antiquark distributions have large uncertainties at this stage, and it is particularly difficult to fi...

Parton Distribution Functions

Dynamical parton distribution functions

Recent measurements for F2(x, Q ) have been analyzed in terms of the ‘dynamical’ and ‘standard’ parton model approach at NLO and NNLO of perturbative QCD. Having fixed the relevant NLO and NNLO parton distributions, the implications and predictions for the longitudinal structure function FL(x,Q ) are presented. It is shown that the previously noted extreme perturbative NNLO/NLO instability of F...

Nuclear Parton Distribution Functions

We study nuclear e ects of charged current deep inelastic neutrino-iron scattering in the framework of a χ analysis of parton distribution functions (PDFs). We extract a set of iron PDFs which are used to compute xBj-dependent and Q -dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. We compare our results with nuclear c...