Abstract
In composite Higgs (CH) models, large mixings between the top quark and the new strongly interacting sector are required to generate its sizeable Yukawa coupling. Precise measurements involving top as well as left-handed bottom quarks therefore offer an interesting opportunity to probe such new physics scenarios. We study the impact of third-generation-quark pair production at future lepton colliders, translating prospective effective-field-theory sensitivities into the CH parameter space. Our results show that one can probe a significant fraction of the natural CH parameter space through the top portal, especially at TeV centre-of-mass energies.
Highlights
We study the impact of third-generation-quark pair production at future lepton colliders, translating prospective effective-field-theory sensitivities into the composite Higgs (CH) parameter space
Composite Higgs (CH) models motivated by the gauge hierarchy problem predict new physics in the vicinity of the TeV scale
We examined the prospects of discovering Higgs compositeness at future lepton colliders through this top portal in precision measurements of top- and bottom-quark pair production
Summary
To cover various concrete scenarios simultaneously, we adopt a model-independent approach to the description of the strong sector effects on top- and bottom-quark physics. An EFT involving SM states only is employed, with operators of dimension six at most. The validity of this approach is ensured by our assumption that no resonance lies below the maximal centre-of-mass energy envisioned for the future lepton colliders that we consider. A discussion of e+e− → t tproduction in a specific CH model can be found in ref. We present the rules used to estimate the magnitudes of the effective operators coefficients generated by the strong sector, and discuss how these rules are affected by a particular choice for the EFT operator basis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
