Six--jet decay of off--shell WW pairs at $e^+ e^-$ colliders

Abstract

Six--jet events via WW pairs, $e^+e^- \ar W^+W^- \ar q_1 \overline{q_1} q_2 \overline{q_2} g g$ are studied at tree level using helicity amplitudes. This is the dominant production mechanism for six--jet final states at Lep II energy. ISR effects are taken into account. Total production rates as a function of $y_{cut}$ are given. The relevance of these processes for the issue of colour reconnection is discussed. The cross section for five--jet production via WW pairs at Lep II is also presented.