Telling the spin of the “Higgs boson” at the LHC

We assume that the Higgs boson or a possible resonance---playing a role in strongly interacting models of electroweak symmetry breaking---has been discovered at the LHC, and we propose a search strategy to determine its spin based on two simple asymmetries in the $ZZ$, ${W}^{+}{W}^{\ensuremath{-}}$, and $t\overline{t}$ decay channels. We consider some benchmark values for its mass (above the $ZZ$ threshold, in the interval from $182\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ to $1\text{ }\text{ }\mathrm{TeV}/{c}^{2}$) and discuss the relative advantages of the different decay processes. A full analysis, including the background, is given. For a center-of-mass energy of 14 TeV, we find that the lowest integrated luminosity required to discriminate between the different spins is, depending on the process and the resonance mass, between $40\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ and $250\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$.