Early discovery of top partners and test of the Higgs nature

Abstract

Top partners from a new strong sector can be discovered soon, at the 8 TeV LHC, by analyzing their single production, which exhibits a large enhancement in the cross section compared to the analogous productions of bottom partners and exotic quarks. We analyze the subsequent decay of the top partners into a 125 GeV Higgs. This channel proves to be very promising for both the discovery of top partners and a test of the Higgs sector. For a reference value $\lambda_{\tilde{T}}=3$ of the Higgs coupling to the top partner, we could have a discovery (observation) at the 8 TeV LHC, with 30 fb$^{-1}$, for top partner masses up to 760 (890) GeV. If the LHC and Tevatron excesses near 125 GeV are really due to a composite Higgs, naturalness arguments demand top partners below $\sim 1$ TeV. Our results highlight thus that the 8 TeV LHC already has a large sensitivity on probing the composite Higgs hypothesis. The LHC reach is even wider at $\sqrt{s}=14$ TeV. With $\lambda_{\tilde{T}}=3$ the LHC with 100 fb$^{-1}$ can observe (at 5$\sigma$) a Higgs from a top partner decay for masses of this latter up to $\simeq 1450$ GeV. In the case the top partner was as light as $\simeq 500$ GeV, the 14 TeV LHC would be sensitive to the measure of the $\lambda_{\tilde{T}}$ coupling in basically the full range $\lambda_{\tilde{T}}>1$ predicted by the theory.