Search For Higgs Boson Pair Production in the $\gamma \gamma b\bar{b}$ Final State using $pp$ Collision Data at $\sqrt{s}=8$ TeV from the ATLAS Detector

Abstract

Searches are performed for resonant and non-resonant Higgs boson pair production in the $\gamma \gamma b\bar{b}$ final state using 20 fb${}^{-1}$ of proton-proton collisions at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the CERN Large Hadron Collider. A 95% confidence level upper limit on the cross section times branching ratio of non-resonant production is set at 2.2 pb, while the expected limit is 1.0 pb. The difference derives from a modest excess of events, corresponding to 2.4 standard deviations from the background-only hypothesis. The limit observed in the search for a narrow $X\to hh$ resonance ranges between 0.7 and 3.5 pb as a function of the resonance mass.

6 pages plus author list + cover page (19 pages total), 3 figures, published version, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-29/