Measurement of differential cross sections for dijet production in neutral current DIS at high Q2 and determination of αS

Dijet production has been studied in neutral current Deep Inelastic ep Scattering for 470 < Q2 < 20000 GeV2 with the ZEUS detector at HERA using 38 pb-1. The jet search is performed in the Breit frame using the longitudinally invariant Kperpendicular-cluster algorithm. Dijet differential cross sections and rates have been measured in a kinematic region where both theoretical and experimental uncertainties are small. NLO QCD calculations describe in shape and magnitude the measured differential cross sections. A QCD fit to the dijet rate as a function of Q2 allows a precise determination of the strong coupling constant