Parton distributions updated

Parton Distributions

I present an overview of some current topics in the measurement of Parton Distribution Functions.

Longitudinal Polarized Parton Densities Updated

We have re-analyzed the world data on inclusive polarized DIS, in both NLO and LO QCD, including the new HERMES and COMPASS data. The updated NLO polarized densities are given in both the MS and JET schemes. The impact of the new data on the results is discussed. PACS numbers: 13.60.Hb, 13.88+e, 12.38.-t, 14.20.Dh Since the famous European Muon Collaboration (EMC) experiment [1] at CERN in 1987...

Parton Distributions : Experimental aspects

Unintegrated parton distributions

We describe how to calculate the parton distributions fa(x, k 2 t , μ 2), unintegrated over the parton transverse momentum kt, from auxiliary functions ha(x, k 2 t ), which satisfy single-scale evolution equations. The formalism embodies both DGLAP and BFKL contributions, and accounts for the angular ordering which comes from coherence effects in gluon emission. We check that the unintegrated d...

Off-Forward Parton Distributions

Recently, there have been some interesting developments involving offforward parton distributions of the nucleon, deeply virtual Compton scattering, and hard diffractive vector-meson production. These developments are triggered by the realization that the off-forward distributions contain information about the internal spin structure of the nucleon and that diffractive electroproduction of vect...