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Lurking pseudovectors below the TeV scale
If electroweak symmetry breaking is driven by a new strongly-coupled
dynamical sector, one expects their bound states to appear at the TeV scale or
slightly below. However, electroweak precision data imposes severe constraints
on most of the existing models, putting them under strain. Conventional models
require the new composite states to come in pairs of rather heavy, close to
degenerate spin-1 resonances. In this paper I argue that spin-1 states can
actually be lighter without clashing with experimental bounds. As an example, I
consider a composite model with a light pseudovector resonance that couples to
the Standard Model gauge boson, fermion and scalar fields. I show how such a
resonance leaves basically no imprint on the NLO corrections to the Standard
Model. This happens not through parameter tuning, but rather as a consequence
of generic properties of realistic UV completions. This pseudovector is mostly
unconstrained by existing data and could be as light as 600 GeV. In the last
part of the paper I briefly discuss its most characteristic signatures for
direct detection at colliders.Comment: 8 pages, 2 figure
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