Measurements of Αs and Parton Distribution Functions Using Hera Jet Data

The QCD processes that give rise to scaling violations in DIS at leading order, namely QCD Compton (QCDC) and boson–gluon fusion (BGF), also give rise to distinct jets in the final state provided that the energy and momentum transfer are large enough. These processes are illustrated in Fig. 1. Both BGF and QCDC depend on αs(MZ), but the BGF process also depends directly on the gluon parton distribution function (PDF), whereas QCDC depends on quark PDFs. The QCDC process dominates at large Q, where the most important quark PDFs are the well-determined u and d valence distributions (for HERA kinematics). Thus measuring jet rates