  Vector boson scattering (VBS) plays a central role in the search for new
physics at collider experiments such as ATLAS and CMS at the LHC. Usually
predictions for this kind of process are obtained using mainly perturbative
approaches in fixed gauges. Here we present a fully gauge-invariant study of
VBS in the scalar-channel involving three different types of Higgs-like
particles characterized by their mass; above (heavy), inside (resonance) or
below (stable) the elastic region. To this end, we combine results obtained in
a reduced SM setup from (augmented) perturbation theory with those from
non-perturbative lattice simulations.
