Helac - a Monte Carlo Generator for Multi-jet Processes

The possibility of identifying new physics relies on predictions of multi jet final states at current and future collider experiments like TeVatron or LHC. Signals for many models beyond the SM involve a large number of jets resulting from decay chains of particles with high masses. Their Monte Carlo (MC) simulation, both for signal and background is of crucial importance for the success of experiments. One of the ways to simulate multi jet events is to use exact matrix elements at some given order of perturbation theory in the strong coupling constant αs. The matrix elements for fully exclusive final states for many jets which we have at our disposal in most cases are at leading order. The advantage of this approach consists of having exact results with all interference effects taken into account properly. The main disadvantage is that more and more diagrams have to be considered when