  A diboson excess has been observed ---albeit with very limited statistical
significance--- in $WW$, $WZ$ and $ZZ$ final states at the LHC experiments
using the accumulated 8 TeV data. Assuming that these signals are due to
resonances resulting from an extended symmetry breaking sector in the standard
model and exact custodial symmetry we determine using unitarization methods the
values of the relevant low-energy constants in the corresponding effective
Lagrangian. Unitarity arguments also predict the widths of these resonances. We
introduce unitarized form factors to allow for a proper treatment of the
resonances in Monte Carlo generators and a more precise comparison with
experiment.
