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arXiv · hep-ph/9706550

Gauge Invariance and the Unstable Particle

Robin G. Stuart
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Abstract

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 $σ(e^+e^-\to Z^0Z^0)$ and thereby provide a solution to the long-standing problem of the unstable particle.

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Robin G. Stuart. 1997-06-30. Gauge Invariance and the Unstable Particle. https://doi.org/10.1063/1.53257

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