Dilaton at the LHC

Abstract: The dilaton, a pseudo-Nambu-Goldstone boson appearing in spontaneous scale symmetry breaking at a TeV scale f, may be found in Higgs boson searches. The dilaton couples to standard model fermions and weak bosons with the same structure as the Higgs boson except for the overall strength. Additionally, the dilaton couples to a Higgs boson pair. The couplings of the dilaton to a gluon pair and a photon pair, appearing at loop level, are largely enhanced compared to the corresponding Higgs couplings. We present regions of the mass and VEV of the dilaton allowed by WW, ZZ, and gammagamma limits from the LHC at 7 TeV with 1.0-2.3 fb-1 integrated luminosity. A scale of f less than 1 TeV is nearly excluded. We discuss how the dilaton chi can be distinguished from the Higgs boson h by observation of the decays chi -> gammagamma and chi -> hh -> (WW)(WW).