Longitudinal WW scattering in light of the "Higgs" discovery

TL;DR

This paper revisits WW scattering analysis post-Higgs discovery, showing that anomalous vector boson couplings can still lead to new resonances detectable at the LHC, despite the Standard Model's perturbative unitarity.

Contribution

It demonstrates that even with a Higgs-like particle, anomalous couplings can produce detectable resonances, extending unitarization techniques to scenarios beyond the Standard Model.

Findings

New resonances can appear in WW scattering with anomalous couplings.

Constraints from unitarity guide the expected properties of these resonances.

Potential for probing extended symmetry sectors with current and future LHC data.

Abstract

WW scattering is dominated at high energies by their longitudinal components, which are the most sensitive to the nature of the electroweak symmetry breaking. Prior to the discovery at the LHC of a Higgs-like particle, unitarization tools were extensively used to show that, in the absence of a light Higgs boson, new resonances resulting from the would-be strongly-interacting electroweak sector would appear, and furthermore these techniques would approximately predict their masses, widths, and signal strengths. With the discovery of a Higgs-like particle now firmly established, we re-investigate these techniques assuming this particle couples exactly as in the SM, but still being open to the possibility of an extended symmetry breaking sector. While the SM itself is free from problems with perturbative unitarity in the electroweak sector, "anomalous" self-couplings of the vector bosons -- low-energy remnants of such higher-energy symmetry breaking sectors -- are easily shown to re-introduce them. We demonstrate how new resonances should still appear in the scattering of EW vector bosons after imposing constraints from unitarity, and we discuss their ability to be probed with current and future LHC data.