Resonant Higgs boson pair production in the hh → b(b)over-bar WW → b(b)over-barl+vl-(v)over-bar decay channel

The addition of a scalar singlet provides one of the simplest extensions of the Standard Model. In this work we briefly review the latest constraints on the mass and mixing of the new Higgs boson and study its production and decay at the LHC. We mainly focus on double Higgs production in the hh -> b (b) over bar WW -> b (b) over barl(+)vl(-)(v) over bar decay channel. This decay is found to be efficient in a region of masses of the heavy Higgs boson of 260-500 GeV, so it is complementary to the 4b channel, more efficient for Higgs bosons with masses greater than 500 GeV. We analyse this di-leptonic decay channel in detail using kinematic variables such as MT2 and the MT2 -assisted on-shell reconstruction of invisible momenta. Using proper cuts, a significance of similar to 3 sigma for 3000 fb(-1) can be achieved at the 14TeV LHC for m(H) = 260-400 GeV if the mixing is close to its present limit and BR(H -> hh) approximate to 1. Smaller values for the mixing would require combining various decay channels in order to reach a similar significance. The complementarity among H -> hh, H -> ZZ and H -> WW channels is studied for arbitrary BR(H -> hh) values.