Abstract
Searches for both resonant and nonresonant Higgs boson pair production are performed in the hh→bbττ, γγWW* final states using 20.3 fb−1 of pp collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No evidence of their production is observed and 95% confidence-level upper limits on the production cross sections are set. These results are then combined with the published results of the hh→γγbb, bbbb analyses. An upper limit of 0.69 (0.47) pb on the nonresonant hh production is observed (expected), corresponding to 70 (48) times the SM gg→hh cross section. For production via narrow resonances, cross-section limits of hh production from a heavy Higgs boson decay are set as a function of the heavy Higgs boson mass. The observed (expected) limits range from 2.1 (1.1) pb at 260 GeV to 0.011 (0.018) pb at 1000 GeV. These results are interpreted in the context of two simplified scenarios of the Minimal Supersymmetric Standard Model.Received 16 September 2015DOI:https://doi.org/10.1103/PhysRevD.92.092004This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.© 2015 CERN, for the ATLAS Collaboration
Highlights
The Higgs boson discovered at the LHC in 2012 [1,2] opens a window for testing the scalar sector of the Standard Model (SM) and its possible extensions
This predicts self-coupling between Higgs bosons, the measurement of which is crucial in testing the mechanism of electroweak symmetry breaking (EWSB)
Production of H followed by its decay H → hh would lead to a new resonant process of Higgs boson pair production, in contrast to the nonresonant hh production predicted by the SM (Fig. 1)
Summary
The Higgs boson discovered at the LHC in 2012 [1,2] opens a window for testing the scalar sector of the Standard Model (SM) and its possible extensions. Higgs boson pairs can be produced through other interactions such as the Higgs-fermion Yukawa interactions [Fig. 1(b)] in the Standard Model These processes are collectively referred to as nonresonant production in this paper. Production of H followed by its decay H → hh would lead to a new resonant process of Higgs boson pair production, in contrast to the nonresonant hh production predicted by the SM (Fig. 1). For hh → γγWWÃ, the h → WWÃ → lνqq0 decay signature is considered in this study The results of these new analyses are combined with the published results of hh → γγbb and hh → bbbb for both nonresonant and resonant production. The resonant search assumes that gluon fusion is the production mechanism for a heavy Higgs boson that can subsequently decay to a pair of lighter Higgs bosons, i.e., gg → H → hh.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
