Structure Functions

TL;DR

This paper presents high-precision measurements of nucleon structure functions, extracting detailed parton distribution functions, and analyzing spin and flavor content, with implications for LHC predictions and understanding proton structure.

Contribution

It provides an improved, precise parametrization of proton parton distribution functions using combined H1 and ZEUS data, enhancing predictions for high-energy collider phenomena.

Findings

Enhanced precision in unpolarised structure functions at low Bjorken x

Constraints on parton distributions from Tevatron data at high x

Insights into the proton's spin and flavor structure from polarized and final state data

Abstract

Recent progress in the understanding of the nucleon is presented. The unpolarised structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions via NLO QCD fits. The obtained parametrisation displays an improved precision, in particular at low Bjorken x, and leads to precise predictions of cross sections for LHC phenomena. Recent data from proton-antiproton collisions at Tevatron indicate further precise constraints at large Bjorken x. The flavour content of the proton is further studied using final states with charm and beauty in DIS ep and pp collisions. Data from polarised DIS or proton-proton collisions are used to test the spin structure of the proton and to constrain the polarised parton distributions.