PHASE , a Monte Carlo event generator for six - fermion physics at the LHC . ∗

PHASE is a new event generator dedicated to the study of Standard Model processes with six fermions in the final state at the LHC. The code is intended for analyses of vector boson scattering, Higgs search, three gauge boson production, and top physics. This first version of the program describes final states characterized by the presence of one neutrino, pp → 4q + lνl, at O(α6). PHASE is based on a new iterative-adaptive multichannel technique, and employs exact leading order matrix elements. The code can generate unweighted events for any subset of all available final states. The produced parton-level events carry full information on their colour and flavour structure, enabling the evolution of the partons into fully hadronised final states. An interface to hadronization packages is provided via the Les Houches Protocol. ∗Work supported by the Ministero dell’Istruzione, dell’Università e della Ricerca under contract 2004021808 009. The work of EA is supported by the MIUR under Contract “Rientro dei cervelli” Decreto MIUR 26-01-2001 N.13 .