MultipleZ′→tt¯signals in a 4D composite Higgs model

Abstract

We study the production of top-antitop pairs at the Large Hadron Collider as a test bed for discovering heavy Z 0 bosons belonging to a composite Higgs model, as in this scenario, such new gauge interaction states are sizeably coupled to the third-generation quarks of the Standard Model. We study their possible appearance in cross sections, as well as (charge and spin) asymmetry distributions. Our calculations are performed in the minimal four-dimensional formulation of such a scenario, namely the four-dimensional composite Higgs model, which embeds five new Z 0 s. We pay particular attention to the case of nearly degenerate resonances, highlighting the conditions under which these are separable in the aforementioned observables. We also discuss the impact of the intrinsic width of the new resonances on the event rates and various distributions. We confirm that the 14 TeV stage of the LHC will enable one to detect two such states, assuming standard detector performance and machine luminosity. A mapping of the discovery potential of the LHC for these new gauge bosons is given. Finally, from the latter, several benchmarks are extracted which are amenable to experimental investigation.

Top pair production at a future e+e− machine in a composite Higgs scenario

“…This is the reason why a close look at this production process within the 4DCHM was taken in Ref. [12]. Herein, it was shown that the additional Z resonances present in this CHM scenario could greatly affect the phenomenology of tt production at the LHC, through their effects onto both the cross section and (charge and spin) asymmetries, so long that they can be produced resonantly and subsequently decay into top-antitop pairs.…”

Using asymmetry observables to discover and distinguish Z' signals in top pair production with the lepton-plus-jets final state at the LHC

“…In short, we believe that our results represent a significant phenomenological advancement in proving that charge and spin asymmetry observables can have a strong impact in accessing and profiling Z → tt signals during Run 2 of the LHC. This is all the more important in view of the fact that several BSM scenarios, chiefly those assigning a composite nature to the recently discovered Higgs boson, embed one or more Z state which are strongly coupled to top (anti)quarks [10].…”

Resonances from quiver theories at the LHC

“…[15] a two-site quiver is proposed, and its phenomenology of the extended gauge sector is studied in Ref. [16]. A three-site construction more similar to ours is that of Ref.…”