DESY-HERA. Measurement of the di-jet cross section in photoproduction data from collisions of 27.5 GeV positrons with 820 GeV protons. The data were taken during a dedicated run in 1996 and 1997 and have an integrated luminosity of 38.6 +- 0.6 pb-1. The variable X(C=GAMMA), is defined as:& lt;p& gt; X(C=GAMMA)=(ET(JET1)*EXP(-ETARAP(JET1)+ET(JET2)*EXP(-ETARAP(JET2))/2*Y*E_e where Y is the energy fraction of the radiated photon in the proton rest frame and E_e is the positron beamenergy. X(C=GAMMA) is the fractional momentum of the photon carried by the inte racting parton. The jets are defined so that ET(JET1) & gt; ET(JET2). In all the distributions, unless otherwise stated the following kinematical ranges apply:& lt;p& gt; 134 & lt; W_GAMMA-P & lt; 277 GeV& lt;br& gt; ET(JET1) & gt; 14 GeV& lt;br& gt; ET(JET2) & gt; 11 GeV& lt;br& gt; -1 & lt; ETRAP(JET1 and JET2) & lt; 2.4.
|Date made available||2002|