Coupling WW, ZZ unitarized amplitudes to $$\gamma \gamma $$ γ γ in the TeV region

Abstract

Abstract We define and calculate helicity partial-wave amplitudes for processes linking the Electroweak Symmetry Breaking Sector (EWSBS) to $$\gamma \gamma $$ γ γ , employing (to NLO) the Higgs-EFT (HEFT) extension of the Standard Model and the Equivalence Theorem, while neglecting all particle masses. The resulting amplitudes can be useful in the energy regime ( $$500~\mathrm{{GeV}}{-}3~\mathrm{{TeV}}$$ 500 GeV - 3 TeV ). We also deal with their unitarization so that resonances of the EWSBS can simultaneously be described in the $$\gamma \gamma $$ γ γ initial or final states. Our resulting amplitudes satisfy unitarity, perturbatively in $$\alpha $$ α , but for all s values. In this way we improve on the HEFT that fails as interactions become stronger with growing s and we provide a natural framework for the decay of dynamically generated resonances into WW, ZZ and $$\gamma \gamma $$ γ γ pairs.

Keywords

• Partial Wave
• Chiral Expansion
• Riemann Sheet
• Minimal Composite Higgs Model
• Elastic Amplitude