Searches for Higgs boson pair production in the $hh\to bb\tau\tau, \gamma\gamma WW*, \gamma\gamma bb, bbbb$ channels with the ATLAS detector

TL;DR

This paper reports on searches for Higgs boson pair production in multiple decay channels using ATLAS data, setting upper limits on production cross sections and interpreting results within the Standard Model and MSSM frameworks.

Contribution

First combined analysis of multiple Higgs pair decay channels at 8 TeV, providing the most stringent limits to date on Higgs pair production cross sections.

Findings

No evidence of Higgs pair production was observed.

Upper limits on non-resonant Higgs pair production are set at 0.69 pb.

Resonance search limits vary from 2.1 pb at 260 GeV to 0.011 pb at 1000 GeV.

Abstract

Searches for both resonant and non-resonant Higgs boson pair production are performed in the $hh\to bb\tau\tau, \gamma\gamma WW^*$ 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 $hh\to \gamma\gamma bb, bbbb$ analyses. An upper limit of 0.69 (0.47) pb on the non-resonant Standard Model like $hh$ production is observed (expected), corresponding to 70 (48) times of the SM $gg\to hh$ 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.