On the Experimental Effects of the Off-shell Structure in Anomalous Neutral Triple Gauge Vertices

Abstract

We discuss differences between on-shell and off-shell treatments in the search for anomalous neutral triple gauge couplings in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collisions. We find that the usual on-shell framework represents an optimal starting point, covering all scenarios in which a reasonable experimental sensitivity is expected. We show that off-shell effects lead to negligible deviations at the experimental level, provided that ${\mathrm{e}}^{+}{\mathrm{e}}^{-}\to \mathrm{f}\bar{\mathrm{f}}\gamma$ and $\mathrm{e^+ e^-}\to\mathr performed in regions where $\mathrm{Z}^*\to\mathrm{f}\bar{\mathrm{f}},\mathrm{f^\prime}\math production is dominant. For consistency reasons, we advocate the use of a natural extension of the on-shell definitions, which takes into account the correct off-shell dependences. Contrary to what has been recently suggested in the literature, we find that no $SU(2{)}_L\times U(1{)}_Y$ constraints among neutral triple gauge couplings can be imposed in a general case.

15 pages, 6 figures. Final version

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• Signatures of the anomalous $Z\gamma$ and ZZ production at the lepton and hadron Colliders
• New and Standard Physics contributions to anomalous Z and gamma self-couplings
• Off-shell structure of the anomalous Z and gamma self-couplings
• Trilinear Neutral Gauge Boson Couplings
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Cited by in corpus (6)

• Study of the e^+e^- --> Z gamma Process at LEP and Limits on Triple Neutral-Gauge-Boson Couplings
• Study of Triple-Gauge-Boson Couplings ZZZ, ZZgam and Zgamgam at LEP
• The processes $e^{-}{e}^{+}\to \gamma \gamma ,Z\gamma ,ZZ$ in SM and MSSM
• Contributions to $ZZ{V}^{\ast }$ ($V=\gamma ,Z,Z^{\prime }$) couplings from $CP$ violating flavor changing couplings
• CP violating effects in the decay Z -> mu^+mu^-gamma induced by ZZgamma and Zgammagamma couplings
• Non-diagonal contributions to $Z\gamma V^{\ast }$ vertex, polarizations and bounds on $Z\overline{t}q$ couplings