Measurement of dijet production with a jet veto at ATLAS

report of the measurement of the fraction of dijet events in pp collisions at sqrt(s) = 7 TeV that do not contain an additional jet in the rapidity region bounded by the dijet system. This quantity tests models of perturbative QCD radiation in dijet systems in two limits: large jet rapidity separation and large jet transverse momentum. In addition, we measure the mean jet multiplicity in the rapidity region bounded by the dijet system. The analysis was performed using 38±4 pb−1 of data taken by ATLAS during the year 2010.