Four-fermion production at gamma gamma colliders: 1. Lowest-order predictions and anomalous couplings

Abstract

We have constructed a Monte Carlo generator for lowest-order predictions for the processes gamma gamma -> 4f and gamma gamma -> 4f+gamma in the Standard Model and extensions thereof by an effective gamma gamma Higgs coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes gamma gamma -> 4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size of various contributions to cross sections, such as from weak charged- or neutral-current, or from strong interactions, is analyzed. Particular attention is paid to W-pair production channels gamma gamma -> W W -> 4f(+gamma) where we investigate the impact of background diagrams, possible definitions of the W-pair signal, and the issue of gauge-invariance violation caused by finite gauge-boson widths. Finally, the effects of triple and quartic anomalous gauge-boson couplings on cross sections as well as the possibility to constrain these anomalous couplings at future gamma gamma colliders are discussed.

40 pages, latex, 27 ps-figures, some references added, final version to appear in Eur. Phys. J. C

References in corpus (8)

• Predictions for all processes e^+e^- -> 4 fermions + gamma
• Signatures of the anomalous $Z\gamma$ and ZZ production at the lepton and hadron Colliders
• LUSIFER: a LUcid approach to SIx-FERmion production
• Bosonic Quartic Couplings at LEP2
• O(alpha) corrections to e+e- --> WW --> 4fermions(+gamma): first numerical results from RACOONWW
• Final State Radiative Effects for the Exact O(alpha) YFS Exponentiated (Un)Stable W+W- Production At and Beyond LEP2 Energies
• Probing anomalous quartic gauge-boson couplings via e+e- --> 4fermions+gamma
• On e+e- --> W+W- --> 4f(+gamma) at LEP2

Cited by in corpus (9)

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• Precise predictions for the Higgs-boson decay H -> W W/Z Z -> 4 leptons
• Radiative corrections to the semileptonic and hadronic Higgs-boson decays H -> W W/Z Z -> 4 fermions
• Electroweak Radiative Corrections for Collider Physics
• Precision calculations for the Higgs decays H-->ZZ/WW-->4leptons
• Next-to-leading order electroweak corrections to pp -> W+W- -> 4 leptons at the LHC in double-pole approximation
• Four-fermion production at gamma gamma colliders: 2. Radiative corrections in double-pole approximation
• Effective-Lagrangian approach to gamma gamma --> WW; I: Couplings and amplitudes
• Effective-Lagrangian approach to gamma gamma --> WW; II: Results and comparison with e+e- --> WW