The self-couplings of vector bosons: does LEP-1 obviate LEP-2?

Abstract

Theories beyond the standard model (“meta-theories”) are severely constrained by the current body of data and must necessarily respect the standard gauge symmetry. We analyze the constraints on two generic types of meta-theory, in which fundamental scalar do or do not exist. The novel low-energy effects can be comprehensively described by grafting onto the standard lagrangian new operators that - in the sense of a Taylor expansion - form a complete set. Completeness calls for consideration of previously discarded operators, and for a thorough exploitation of the equations of motion. We illustrate the current strictures by focusing on the allowed range of departures from the most crucial, untested, precise standard prediction: the size and structure of the triple gauge-boson vertices. We conclude that their direct measurement at LEP-2, while phenomenologically very interesting, is, alas, unlikely to provide new information.