QCD improved parton distribution functions of

Parton Distribution Functions and QCD Global Fitting

High energy hadrons interact through their quark and gluon constituents. The interactions become weak at short distances thanks to the asymptotic freedom property of QCD, which allows perturbation theory to be applied to a rich variety of experiments. The nonperturbative nature of the proton for single hard interactions is thus characterized by Parton Distribution Functions (PDFs) fa(Q, x) of m...

Parton distribution functions from Lattice QCD

We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a first study of the vector parton distribution function using a twisted mass ensemble at pion mass of 373 MeV.

Perturbative renormalization in parton distribution functions using improved actions

We calculate the 1-loop renormalization of a set of extended fermionic bilinears which form a basis corresponding to moments of the parton distribution functions. We use the overlap action for fermions and Luescher-Weisz (LW) action for gluons. Our results are presented as a function of the overlap parameter ρ and the parameters entering the LW action.

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...