Related papers: Restoring gauge invariance in gauge-boson producti…
A report is given on the theoretical aspects of gauge-boson production processes at LEP2 and the next linear collider (NLC). A short discussion is given on the gauge-boson-related physics issues that play a role at both coliders and on the…
It is shown how to construct exactly gauge-invariant S-matrix elements for processes involving unstable gauge particles such as the $W$ and $Z^0$ bosons. The results are applied to derive a physically meaningful expression for the…
We discuss theoretical and phenomenological aspects of the use of boson propagators with energy-dependent widths in predictions for high-energy scattering processes. In general, gauge invariance is violated in such calculations. We discuss…
It is shown how to construct exactly gauge-invariant S-matrix elements for processes involving unstable gauge particles such as the $Z^0$ boson. The results are applied to derive a physically meaningful expression for the cross-section…
High-precision predictions for W-production processes are complicated by the instability of the W bosons, requirements of gauge invariance, and the necessity to include radiative corrections. Salient features and recent progress concerning…
In this paper the problem of the gauge in a bound state calculation is discussed. In particular, in order to verify the gauge invariance in the energy levels expansion, some set of gauge invariant contributions are given.
We present a gauge invariant way to compute one loop corrections to processes involving the production and decay of unstable particles.
For gauge theory, the matrix element for any physical process is independent of the gauge used. Since this is a formal statement and examples are known where gauge invariance is violated, for any specific process this gauge invariance needs…
Reparametrization invariance being treated as a gauge symmetry shows some specific peculiarities. We study these peculiarities both from a general point of view and on concrete examples. We consider the canonical treatment of…
Based on an Invited Plenary Talk given at ``Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders,'' Waikoloa, Hawaii, April 26--30, 1993. This paper reviews theoretical issues concerning the structure of vector bosons, with…
The process $e^+e^-\rightarrow \bar \nu_e e^-W^+ \rightarrow\bar\nu_e e^-u\bar d$ is considered as an example of the problems associated with maintaining gauge invariance in matrix elements involving unstable particles. It is shown how to…
Developments in the analysis of W and quark propagators in the resonance region, and recent considerations concerning the mass and width of the Higgs boson are reviewed. Particular emphasis is placed on the instability of these fundamental…
The production of multiple gauge bosons via weak boson fusion is an important process at the LHC. It is relevant as a background process appearing in many searches and measurements, but also serves as a signal process when studying…
When computing the properties of reactions involving unstable charged particles care has to be taken to use a gauge invariant amplitude. In this talk we present methods to (automatically) obtain such an amplitude, both at the tree level and…
The role of the gauge invariance in noncommutative field theory is discussed. A basic introduction to noncommutative geometry and noncommutative field theory is given. Background invariant formulation of Wilson lines is proposed. Duality…
The issue of the gauge invariance of gravitational waves arises if they are produced in the early universe at second-order in perturbation theory. We address it by dividing the discussion about the gauge invariance in three parts: the…
A review is given of the theoretical expectations of the self couplings of gauge bosons and of the present experimental information on the couplings. The possibilities for future measurements are also discussed.
There are many applications in gauge theories where the usually employed framework involving gauge-dependent Green's functions leads to considerable problems. In order to overcome the difficulties invariably tied to gauge dependence, we…
The processes of electroweak gauge boson production in high energy photon-photon collisions are surveyed.
The procedure to find gauge invariant variables for two-parameter nonlinear perturbations in general relativity is considered. For each order metric perturbation, we define the variable which is defined by the appropriate combination with…