  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.

High Energy Physics - Experiment