Di-jet event rates in deep-inelastic scattering at HERA

Abstract. Di-jet event rates have been measured for deep-inelastic scattering in the kinematic domain \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$5 \lesssim Q^2 \lesssim 100$\end{document} GeV$$^2$$ and $$10^{-4} \lesssim x_{Bj} \lesssim 10^{-2}$$, and for jet transverse momenta squared $$p_t^{*2}\gtrsim Q^2$$. The analysis is based on data collected with the H1 detector at HERA in 1994 corresponding to an integrated luminosity of about 2 pb$$^{-1}$$. Jets are defined using a cone algorithm in the photon-proton centre of mass system requiring jet transverse momenta of at least 5 GeV. The di-jet event rates are shown as a function of $$Q^2$$ and $$x_{Bj}$$. Leading order models of point-like interacting photons fail to describe the data. Models which add resolved interacting photons or which implement the colour dipole model give a good description of the di-jet event rate. This is also the case for next-to-leading order calculations including contributions from direct and resolved photons.