COMBINED QCD AND ELECTRO-WEAK FITS AT HERA

The world's only ep-collider HERA can explore the deep inelastic scattering over a wide kinematic region due to its large center-of-mass energy. Therefore, a unique study of a simultaneous determination of parton distribution functions and electro-weak parameters can be performed. The HERA-II high precision data with longitudinally polarized electron beams brought significant improvements on the sensitivity to both parameters.