  In the absence of a light Higgs boson, the mechanism of electroweak symmetry
breaking will be best studied in processes of vector boson scattering at high
mass. Various models predict resonances in this channel. Scalar and vector
resonances have been investigated in the WW, WZ and ZZ channels. The ability of
ATLAS to measure the di-boson cross-section over a range of centre-of-mass
energies has been studied with particular attention paid to the reconstruction
of jet pairs with low opening angle resulting from the decays of highly boosted
vector bosons.
