Summary of working group I: Hadron structure

Abstract

A summary is given on the main aspects which were discussed by the working group. They include new results on the deep inelastic scattering structure functions F 2 , xF 3 , F L and F cc 2 and their parametrizations, the measurement of the gluon density, recent theoretical work on the small x behavior of structure functions, theoretical and experimental results on α s , the direct photon cross section, and a discussion of the event rates in the high p T range at Tevatron and the high Q 2 range at HERA, as well as possible interpretations.

Structure Functions of the Nucleon and Their Interpretation

“…Such broadening would have to increase with √ s in order to describe all the data 201 . Until these effects are calculated in QCD it is difficult to use these higher energy data to pin down the gluon 202,203,204 . For the lower energy data of WA70 and E706 the broadening is much less, but even here there are the scale uncertainties which lead to an uncertainty of ∼ 25% in the gluon distribution.…”

Relations among higher order QCD corrections

“…The Deep Inelastic Scattering (DIS) [ 1] of a lepton (l) on a hadron target (say proton P ) is given by the process: l + P (p) → l + X where p is the momentum of the target hadron. The X in the above process denotes the final state hadrons which are summed over.…”