Hera Precision Measurements and Impact for LHC Predictions

Abstract: A QCD fit analysis to the combined HERA inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations for $e^\pm p$ scattering to extract HERAPDF sets is presented. The results are used for predictions of $ p\bar{p}$ processes at Tevatron and $pp$ processes at the LHC. The QCD analysis has been extended to include the combined HERA II measurements at high $Q^2$ resulting in the HERAPDF1.5 sets, with full estimation of uncertainties. The precision of the new PDFs at high $x$ is considerably improved, particularly in the valence sector. In addition, inclusion of the HERA jet data allows for a precise determination of the strong coupling. Moreover, inclusion of the preliminary combined HERA charm data provides constraints for the optimal value of the charm mass used in QCD theory models which may account for some of the differences among global PDF fits.