Searching heavier Higgs boson via di-Higgs production at LHC Run-2

The discovery of a light Higgs particle h0(125GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson H0 via di-Higgs production channel at the LHC (14 TeV), H0→h0h0→WW⁎γγ. This directly probes the Hhh cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states WW⁎, we include both pure leptonic mode WW⁎→ℓν¯ℓ¯ν and semi-leptonic mode WW⁎→qq¯′ℓν. We analyze signals and backgrounds by performing fast detector simulation for the full process pp→H→hh→WW⁎γγ→ℓν¯ℓ¯νγγ and pp→H→hh→WW⁎γγ→ℓνqq¯′γγ, over the mass range MH=250-600GeV. For generic two-Higgs-doublet models (2HDM), we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.