Description of the ATLAS jet veto measurement and jet gap jet events at hadronic colliders

We present a new QCD description of the ATLAS jet veto measurement, using the Banfi- Marchesini-Smye equation to constrain the inter-jet QCD radiation. This equation resums emis- sions of soft gluons at large angles and leads to a very good description of data. We also investigate jet gap jet events in hadron-hadron collisions, in which two jets are produced and separated by a large rapidity gap. Using a renormalisation-group improved NLL kernel implemented in the HERWIG Monte Carlo program, we show that the BFKL predictions are in good agreement with the Tevatron data, and present predictions that could be tested at the LHC.