Constraining resonances by using the electroweak effective theory

TL;DR

This paper uses the electroweak effective theory to constrain possible new resonances, showing that current experimental bounds suggest these resonances likely have masses above 2 TeV, consistent with prior estimates.

Contribution

It provides a method to relate low-energy constants in the electroweak effective theory to resonance masses, constraining new physics scales using experimental data.

Findings

Resonance masses are constrained to be above 2 TeV.

Low-energy constants are linked to resonance parameters.

Current bounds are consistent with previous estimates.

Abstract

In the light of the mass gap between Standard Model (SM) states and possible new particles, effective field theories are a suitable approach. We take on the non-linear realization of the electroweak symmetry breaking: the electroweak effective theory (EWET), also known as Higgs effective field theory (HEFT) or electroweak chiral Lagrangian (EWChL). At higher scales we consider a resonance electroweak Lagrangian, coupling SM fields to resonances. Integrating out these resonances and assuming a well-behaved high-energy behavior, some of the bosonic low-energy constants are determined or constrained in terms of resonance masses. Present experimental bounds on these low-energy constants allow us to push the resonance mass scale to the TeV range, $M_R \geq 2\,$TeV, in good agreement with previous estimations.