Subproject B3: Parton Distribution Functions on the Lattice and in the Continuum

Project leader:

Dr. Johannes Blümlein, DESY Zeuthen
Dr. Karl Jansen, DESY Zeuthen
Dr. Sven Moch, DESY Zeuthen

Collaborators:

Dr. Isabella Bierenbaum
Dipl. Phys. NN

The project aims on the detailed understanding of the nucleon sub-structure at short distances, applying perturbative calculations in Quantum Chromodynamics (QCD) analyzing experimental precision data of deep-inelastic and hard scattering processes. These results are compared to non-perturbative calculations in Lattice-QCD.

In a joint investigation applying both methods a detailed determination of the twist-2 moments of various unpolarized and polarized quantities and lower twist-3 moments are aimed on. This includes the measurement of these quantities using systematically stable lattice methods, the perturbative calculation of QCD-corrections in higher orders of anomalous dimensions and the associate massless and massive Wilson coefficients along with the QCD analysis of precision data. In this way the parton distribution functions and the QCD scale Λ_QCD are determined with correlated errors and high accuracy. The moments of parton densities extracted from experimental data can be compared to the moments determined by non-perturbative lattice methods ab initio. This allows for detailed QCD-tests at short space-like distances.

Last Change: October, 19th 2007