Determination of Parton Distribution Functions

Group members: James Stirling, Robert Thorne

In order to predict the results of any hard-scattering process where hadrons are initial state particles it is necessary to know the parton distributions within the hadrons. We are part of the Martin-Stirling-Thorne-Watt (MSTW) collaboration involved in the determination of these parton distributions using all available data from electron-proton (e.g. HERA) and proton-(anti)proton (e.g. Tevatron) colliders and using next-to-next-to-leading order (NNLO) perturbative QCD. This also leads to a determination of the QCD coupling α_S. Work is also done on theoretical improvements to standard perturbation theory, particularly resummations of large ln(1/x) terms at small x, and heavy quark contributions from charm and bottom.

We have recently produced new sets of parton distributions (MSTW2008) at LO, NLO and NNLO (with uncertainties) for use at the LHC, see arXiv:0901.0002.

Further information and pdf codes can be found on the MSTW page atHepForge.