Abstract
A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons ($H$) in proton-proton collisions collected by the CMS experiment at the LHC at $\sqrt{s}$ = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb$^{−1}$. The search considers $HH$ resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and tt events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95% confidence level for the product of the production cross section and branching fraction $\sigma(gg \to X) B(X \to HH \to b\overline{b}b\overline{b}$) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with a mass scale $\Lambda_{R}$ = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV
CMS Collaboration