What if the Higgs couplings to W and Z bosons are larger than in the Standard Model?

TL;DR

This paper derives a sum rule linking Higgs couplings to gauge bosons with gauge boson scattering cross sections, suggesting that larger-than-Standard Model couplings could indicate an extended Higgs sector with an isospin-2 scalar multiplet.

Contribution

It introduces a general sum rule connecting Higgs couplings to scattering cross sections and explores implications of an extended Higgs sector with isospin-2 scalars.

Findings

Larger Higgs couplings imply enhanced I=2 scattering cross section.

Extension with isospin-2 scalar multiplet can explain coupling enhancement.

Sum rule provides a testable relation between couplings and scattering data.

Abstract

We derive a general sum rule relating the Higgs coupling to W and Z bosons to the total cross section of longitudinal gauge boson scattering in I=0,1,2 isospin channels. The Higgs coupling larger than in the Standard Model implies enhancement of the I=2 cross section. Such an enhancement could arise if the Higgs sector is extended by an isospin-2 scalar multiplet including a doubly charged, singly charged, and another neutral Higgs.