Probing anomalous quartic gauge-boson couplings via $\mathrm{e^+e^-} \rightarrow 4$ fermions $+\gamma$

A. Denner; S. Dittmaier; M. Roth; D. Wackeroth

doi:doi:10.1007/s100520100678

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2022 Impact factor 4.4

Particles and Fields

Eur. Phys. J. C 20, 201-215
DOI: 10.1007/s100520100678

Probing anomalous quartic gauge-boson couplings via $\mathrm{e^+e^-} \rightarrow 4$ fermions $+\gamma$

A. Denner¹, S. Dittmaier², M. Roth³ and D. Wackeroth⁴

¹ Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
² Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
³ Institut für Theoretische Physik, Universität Leipzig, 04109 Leipzig, Germany
⁴ Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, USA

(Received: 5 April 2001 / Revised version: 5 April 2001 / Published online: 18 May 2001 -© Springer-Verlag / Società Italiana di Fisica 2001)

Abstract
All lowest-order amplitudes for $\mathrm{e^+e^-}\to 4 f \gamma$ are calculated including five anomalous quartic gauge-boson couplings that are allowed by electromagnetic gauge invariance and the custodial SU(2)_c symmetry. Three of these anomalous couplings correspond to the operators $\mathcal{L}_0$ , $\mathcal{L}_{\mathrm{c}}$ , and $\mathcal{L}_{\mathrm{n}}$ that have been constrained by the LEP collaborations in $\mathrm{WW}\gamma$ production. The anomalous couplings are incorporated in the Monte Carlo generator RACOONWW. Moreover, for the processes $\mathrm{e^+e^-}\to 4 f \gamma$ RACOONWW is improved upon including leading universal electroweak corrections such as initial-state radiation. The discussion of numerical results illustrates the size of the leading corrections as well as the impact of the anomalous quartic couplings for LEP2 energies and at 500 GeV.