Parton distribution functions and quark orbital motion

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...

Transverse parton distribution functions at next-to-next-to-leading order: the quark-to-quark case.

We present a calculation of the perturbative quark-to-quark transverse parton distribution function at next-to-next-to-leading order based on a gauge invariant operator definition. We demonstrate for the first time that such a definition works beyond the first nontrivial order. We extract from our calculation the coefficient functions relevant for a next-to-next-to-next-to-leading logarithmic Q...

Orbital Angular Momentum Parton Distributions in Quark Models

At the low energy, hadronic, scale we calculate Orbital Angular Momentum (OAM) twist-two parton distributions for the relativistic MIT bag model and for nonrelativistic quark models. We reach the scale of the data by leading order evolution in perturbative QCD. We confirm that the contribution of quarks and gluons OAM to the nucleon spin grows with Q, and it can be relevant at the experimental ...