A measurement of multijet production in low-Bjorken x neutral current deep inelastic scattering with ZEUS at HERA

Inclusive dijet and trijet production in deep inelastic electron-proton scattering has been measured at low Bjorken x and low exchange boson virtuality. The data were taken at the HERA electron-proton collider using the ZEUS detector. Jets were identified in the hadronic center-of-mass (HCM) frame using the kT cluster algorithm in the longitudinally invariant inclusive mode. Measurements of dijet and trijet differential cross sections are presented as functions of exchange photon virtuality, Bjorken x, jet transverse energy, and jet pseudorapidity. As a further examination of low-x dynamics, multi-differential cross sections as functions of the jet correlations in transverse momenta, azimuthal angles, and pseudorapidity are also presented. Calculations at order alpha-s cubed generally describe the trijet data well and improve the description of the dijet data compared to the calculation at order alpha-s squared.