Towards the fate of natural composite Higgs model through single $t^{\prime }$ search at the 8 TeV LHC

Abstract

We analyze the observational potential of single $t^{\prime }$ production in both the $t^{\prime }\to bW$ and $t^{\prime }\to th$ decay channels at 8 TeV LHC using an integrated luminosity of 25 ${\text{fb}}^{-1}$. Our analysis is based on a simplified model with minimal coset $SO(5)/SO(4)$ in which the $t^{\prime }$ is a singlet of the unbroken SO(4). The single $t^{\prime }$ production, as a consequence of electroweak symmetry breaking, is less kinematically suppressed, associated with a light forward jet and has boosted decay products at the 8 TeV LHC. Therefore it provides the most promising channel in searching for a heavy $t^{\prime }$. We have exploited the above kinematical features and used the jet substructure method to reconstruct the boosted Higgs in $th$ decay channel. It is shown that a strong constraint on the $t^{\prime }bW$ coupling ($g_{t^{\prime }bW}/g_{tbW,SM}<0.2\sim 0.3$) at the 95% C. L. can be obtained for $m_{t^{\prime }}\subset (700,1000)$ GeV.

Comments: 22 pages, 8 figures, 5 tables, refs added in v2