Discovering the composite Higgs through the decay of a heavy fermion

Abstract

A possible composite nature of the Higgs could be revealed at the early stage of the LHC, by analyzing the channels where the Higgs is produced from the decay of a heavy fermion. The Higgs production from a singly-produced heavy bottom, in particular, proves to be a promising channel. For a value λ = 3 of the Higgs coupling to a heavy bottom, for example, we find that, considering a 125 GeV Higgs which decays into a pair of b-quarks, a discovery is possible at the 8 TeV LHC with 30 fb⁻¹ if the heavy bottom is lighter than roughly 530 GeV (while an observation is possible for heavy bottom masses up to ≃ 650 GeV). Such a relatively light heavy bottom is realistic in composite Higgs models of the type considered and, up to now, experimentally allowed. At $\sqrt {s} = {14}$ TeV the LHC sensitivity on the channel increases significantly. With λ = 3 a discovery can occur, with 100 fb⁻¹, for heavy bottom masses up to ≃ 1040 GeV. In the case the heavy bottom was as light as ≃ 500 GeV, the 14 TeV LHC would be sensitive to the measure of the λ coupling in basically the full range λ > 1 predicted by the theory.