Speaker
Alexander Glazov
(Deutsches Elektronen-Synchrotron (DE))
Description
We present the HERAFITTER project which provides a framework for QCD
analyses related to the proton structure in the
context of multi-processes and multi-experiments.
Based on the concept of factorisable nature of the cross sections into
universal parton distribution functions (PDFs) and process dependent
partonic scattering cross sections, HERAFitter allows determination of
PDFs from the various hard scattering measurements.
Here we report a set of parton distribution functions determined with
the HERAFitter program using HERA data and preserving correlations
between uncertainties for the LO, NLO and NNLO sets. The sets are used
to study uncertainties for ratios of cross sections calculated at
different order in QCD. A reduction of overall theoretical uncertainty
is observed in this case.
Author
Alexander Glazov
(Deutsches Elektronen-Synchrotron (DE))