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arXiv · hep-ph/9305321

On Gauge Invariance of Breit-Wigner Propagators

M. Nowakowski·A. Pilaftsis
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Abstract

We present an approach to bosonic ($Z^0, W^{\pm}$) as well as fermionic (top-quark) Breit-Wigner propagators which is consistent with gauge invariance arguments. In particular, for the $Z^0$-boson propagator we extend previous analyses and show that the part proportional to $k_μ k_ν/M^2$ must be modified near the resonance. We derive a mass shift which agrees with results obtained elsewhere by different methods. The modified form of a resonant heavy fermion propagator is also given.

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M. Nowakowski, A. Pilaftsis. 1993-05-26. On Gauge Invariance of Breit-Wigner Propagators. https://doi.org/10.1007/bf01650437

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