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arXiv · hep-ph/9607253

Analysis of the Z^0 Resonant Amplitude in General R_ξGauges

M. Passera·A. Sirlin
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Abstract

The Z^0 resonant amplitude is discussed in general R_ξgauges. When the original on-shell definition of the Z^0 mass M is employed, a gauge dependence of M emerges in the next-to-leading approximation which, although small, is of the same magnitude as the current experimental error. In the following order of expansion, these unphysical effects are unbounded. The gauge dependence of M disappears when modified, previously proposed definitions of mass or self-energies, are used. The relevance of these considerations to the concept of the mass of unstable particles is pointed out.

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M. Passera, A. Sirlin. 1996-10-15. Analysis of the Z^0 Resonant Amplitude in General R_ξGauges. https://doi.org/10.1103/physrevlett.77.4146

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