Parton Distribution Functions and Lattice QCD

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.

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 function with nonperturbative renormalization from lattice QCD

Parton Distributions from Lattice QCD

We extract the x dependence of the valence nonsinglet u − d distribution function in the nucleon from the lowest few moments calculated on the lattice, using an extrapolation formula which ensures the correct behavior in the chiral and heavy quark limits. We discuss the implications for the quark mass dependence of meson masses lying on the J P C = 1 −− Regge trajectory.

Understanding Parton Distributions from Lattice QCD

I examine the past lattice QCD calculations of three representative observables, the transverse quark distribution, momentum fraction, and axial charge, and emphasize the prospects for not only quantitative comparison with experiment but also qualitative understanding of QCD.