Selection rules for helicity amplitudes in massive gauge theories

Speaker: Paolo Lodone, ITPP, EPFL Lausanne

Speaker arrival: 03/02/2013

Speaker departure: 07/02/2013

Assigned office: 23

Title: Selection rules for helicity amplitudes in massive gauge theories

Place: Sala de Seminarios, Dpto. Física Teórica y del Cosmos

Date: 05/02/2013

Time: 16:00

Abstract:
After a rediscussion of the vanishing theorems for helicity amplitudes in unbroken gauge theories, we study the case of spontaneously broken gauge theories at high energy. The vanishing theorems generalize to a well-defined pattern of m/E-suppression of the amplitudes that vanish in the massless case, where E is the energy scale of the process and m is the mass of the gauge vectors. We use only elementary arguments, and as an application we show how these methods can be employed to understand some aspects of the effective W approximation in the polarized case.