Di-Higgs final states augMT2ed – Selecting hh events at the high luminosity LHC

Higgs boson self-interactions can be investigated via di-Higgs (pp→hh+X) production at the LHC. With a small O(30)fb Standard Model production cross section, and a large tt¯ background, this measurement has been considered challenging, even at a luminosity-upgraded LHC. We demonstrate that by using simple kinematic bounding variables, of the sort already employed in existing LHC searches, the dominant tt¯ background can be largely eliminated. Simulations of the signal and the dominant background demonstrate the prospect for measurement of the di-Higgs production cross section at the 30% level using 3ab−1 of integrated luminosity at a high luminosity LHC. This corresponds to a Higgs self-coupling determination with 60% accuracy in the bb¯τ+τ− mode, with potential for further improvements from e.g. subjet technologies and from additional di-Higgs decay channels.