An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment

The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e + and e- beams, together with differential cross-section data on inclusive jet production in e + p scattering and dijet production in \(\gamma p\) scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the proton. The input of jet-production data constrains the gluon and allows an accurate extraction of \(\alpha_s(M_Z)\) at NLO; \(\alpha _{s} {\left( {M_{Z} } \right)} = 0.1183 \pm 0.0028{\left( {\exp .} \right)} \pm 0.0008{\left( {{\text{model}}} \right)}.\) An additional uncertainty from the choice of scales is estimated as \(\pm 0.005\). This is the first extraction of \(\alpha_s(M_Z)\) from HERA data alone.