Testing gluon self-interactions in three-jet events at hadron colliders

The effective operator tr(G3) is the only CP-even dimension-6 gluonic operator that cannot be related to four-quark operators. A peculiar property of this operator is that it does not contribute to two-jet production at hadron colliders, at the level of one operator insertion and leading order in αs; therefore we study its effects on three-jet events. To calculate the helicity amplitudes induced by this operator we make extensive use of collinear factorization. We propose several ways of detecting the tr(G3) signal, one of which exploits its non-trivial behavior under azimuthal rotations of two almost collinear jets.