Discovering the composite Higgs through the decay of a heavy fermion

TL;DR

This paper explores how the decay of a heavy fermion, specifically a heavy bottom quark, can reveal the composite nature of the Higgs boson at the LHC, providing promising detection channels and sensitivity estimates.

Contribution

It introduces a novel analysis of Higgs production via heavy fermion decay, highlighting the potential for early LHC discovery of composite Higgs models through this channel.

Findings

At 8 TeV, heavy bottom masses up to 530 GeV can be discovered with 30 fb^{-1}.

At 14 TeV, the LHC can discover heavy bottoms up to 1040 GeV with 100 fb^{-1}.

The channel allows probing the Higgs coupling  of the order of 1 or more.

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 \lambda=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 \lambda=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 \lambda\ coupling in basically the full range \lambda>1 predicted by the theory.