Multijet production at low [formula omitted] in deep inelastic scattering at HERA

Abstract

Inclusive dijet and trijet production in deep inelastic ep scattering has been measured for 10 < Q 2 < 100 GeV 2 and low Bjorken x, 10 −4 < x Bj < 10 −2 . The data were taken at the HERA ep collider with centre-of-mass energy s = 318 GeV using the ZEUS detector and correspond to an integrated luminosity of 82 pb −1 . Jets were identified in the hadronic centre-of-mass (HCM) frame using the k T cluster algorithm in the longitudinally invariant inclusive mode. Measurements of dijet and trijet differential cross sections are presented as functions of Q 2 , x Bj , jet transverse energy, and jet pseudorapidity. As a further examination of low- x Bj dynamics, multi-differential cross sections as functions of the jet correlations in transverse momenta, azimuthal angles, and pseudorapidity are also presented. Calculations at O ( α s 3 ) generally describe the trijet data well and improve the description of the dijet data compared to the calculation at O ( α s 2 ) .