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Off-shell structure of the anomalous Z and gamma self-couplings

G. J. Gounaris·J. Layssac·F. M. Renard
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Abstract

We establish the general off-shell structure of the three neutral gauge boson self-couplings V1*V2*V3*, with applications to the Z*Z*Z*, Z*Z*gamma*, gamma*gamma*Z* cases. New coupling forms appear which do not exist when two gauge bosons are on-shell. We give the contribution arising from a fermionic triangle loop. It covers both the standard model (SM) and possible new physics (NP) contributions like those arising in the MSSM. For what concerns NP contributions with a high scale, we discuss the validity of an effective Lagrangian involving a limited set of parameters. Finally we write the general expression of the V1*V2*V3*-vertex contribution to the e+e- to (f(bar) f)+(f'(bar) f') amplitude.

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G. J. Gounaris, J. Layssac, F. M. Renard. 2001-09-17. Off-shell structure of the anomalous Z and gamma self-couplings. https://doi.org/10.1103/physrevd.62.073012

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