G.J. Gounaris1 - J. Layssac2 - P.I. Porfyriadis1 - F.M. Renard2
1 Department of Theoretical Physics, Aristotle
University of Thessaloniki,
54006, Thessaloniki, Greece
2 Physique Mathématique et Théorique, UMR 5825, Université Montpellier II, 34095 Montpellier Cedex 5, France
Received: 3 September 1999 / Published online: 3 February 2000 - © Springer-Verlag 2000
We study the helicity amplitudes of the process in the Standard Model at high energy. These amplitudes receive contributions from the W and charged quark and lepton loops, analogous to those encountered in the cases studied before. But also receives contributions from the Higgs s-channel poles involving the effective Higgs- vertex. At energies , the amplitudes in all three processes are mainly helicity-conserving and almost purely imaginary; which renders them a very useful tool in searching for New Physics. As an example, a SUSY case is studied, and the signatures due to the virtual effects induced by a chargino-, charged slepton- or a lightest stop-loop in , are explored. These signatures, combined with the analogous ones in and , should help identifying the nature of possible New Physics particles.
Copyright Società Italiana di Fisica, Springer-Verlag 2000