Radiative Corrections to $γγ\to W^+ W^-$ in the Electroweak Standard Model

TL;DR

The paper delivers a complete calculation of the ${ m O}(\,α\,) $ radiative corrections to the process ${\gamma\gamma \to W^+W^-W^-}$ within the electroweak Standard Model for arbitrary photon and W polarizations. Using a non-linear gauge to reduce diagram multiplicities and a consistent on-shell renormalization scheme, the authors separate virtual and soft-photonic corrections and treat Higgs-resonant contributions in a gauge-invariant manner. They find that universal leading corrections from running α or heavy masses do not arise in this setup; the corrections are typically around 10% but can be significantly larger when the lowest-order cross sections are suppressed, especially near the Higgs resonance or at high energies with angular cuts. The results provide precise SM expectations for γγ colliders and underpin studies of non-Abelian gauge couplings in multi-boson final states.

Abstract

The cross-section for $γγ\to W^+ W^-$ with arbitrary polarized photons and W bosons is calculated within the electroweak Standard Model including the complete virtual and soft-photonic ${\cal O}(α)$ corrections. We present a detailed numerical discussion of the complete radiative corrections and an analytical investigation of the leading corrections. It turns out that in the on-shell renormalization scheme for fixed $M_W$ no leading corrections associated with the running of $α$ or heavy top-quark and Higgs-boson masses occur. The corrections are typically of the order of 10\%. They reach, however, larger values where the lowest-order cross-sections are suppressed.

Figures (11)

• Figure 1: Lowest-order diagrams for $\gamma\gamma\to{\rm W^+}$ W^+${\rm W^-}$ W^-$$ in NL gauge
• Figure 2: The $t$-channel diagrams for the upper $AWW^*$ vertex
• Figure 3: Non-crossing-symmetric box diagrams
• Figure 4: Crossing-symmetric box diagrams
• Figure 5: The $AAH^*$ vertex diagrams