New Physics In Resonant Production Of Higgs Boson Pairs

We advocate a search for an extended scalar sector at the LHC via hh production, where h is the 125 GeV Higgs boson. A resonance feature in the hh invariant mass is a smoking gun of an s-channel heavy Higgs resonance, H. With one h decaying to two photons and the other decaying to b quarks, the resonant signal may be discoverable above the hh continuum background for M-H < 1 TeV. The product of the scalar and top Yukawa couplings can be measured to better than 10%-20% accuracy, and its sign can be inferred from the hh line shape via interference effects.