Contributions of LEP1.5, LEP2 and linear-collider data to indirect constraints on non-Abelian gauge-boson couplings

Abstract

It is possible to place direct constraints on WW-photon and WWZ couplings by studying their tree-level contributions to the process e^+e^- ---> W^+W^-. However, these couplings also contribute at the loop level to e^+e^- ---> f fbar processes where `f' is any Standard-Model fermion. In this paper the available LEP1.5 and LEP2 data, the anticipated LEP2 data and possible linear collider data for these latter processes is combined with low-energy and Z-pole data to place indirect constraints on nonstandard WW-photon and WWZ couplings. The direct and indirect constraints are then compared. An effective Lagrangian is used to describe the new physics. In order that the implications of this analysis are as broad as possible, both the light-Higgs scenario, described by an effective Lagrangian with a linear realization of the symmetry-breaking sector, and the strongly interacting scenario, described by the electroweak chiral Lagrangian, are considered.