Heavy resonances and the electroweak effective theory

Abstract

Taking into account the negative results of direct searches for beyond the Standard Model fields and the consequent mass gap between Standard Model and possible unknown states, the use of electroweak effective theories is justified. Whereas at low energies we consider a non-linear realization of the electroweak symmetry breaking with a singlet Higgs and a strongly-coupled ultraviolet completion, at higher energies the known particles are assumed to be coupled to heavy states: bosonic fields with J P = 0 ± and J P = 1 ± (in electroweak triplets or singlets and in QCD octets or singlets) and fermionic states with J = 1 2 (in electroweak doublets and in QCD triplets or singlets). By integrating out these heavy resonances, the pattern of next-to-leading order lowenergy constants among the light fields can be studied. A phenomenological study trying to estimate the scale of these resonances is also shown.

Resonances in unitarized HEFT at the LHC

“…A first option to link the low-energy HEFT to the scale of new physics is to project the underlying theory to saturate the low-energy constants by the parameters of the new resonances [2]. This procedure's poster child is the QCD ρ meson.…”