Exploring fine-tuning of the Next-to-Minimal Composite Higgs Model

  • Daniel MurnaneEmail author
  • Martin White
  • Anthony G. Williams
Open Access
Regular Article - Theoretical Physics


We perform a detailed study of the fine-tuning of the two-site, 4D, Next-to-Minimal Composite Higgs Model (NMCHM), based on the global symmetry breaking pattern SO(6) → SO(5). Using our previously-defined fine-tuning measure that correctly combines the effect of multiple sources of fine-tuning, we quantify the fine-tuning that is expected to result from future collider measurements of the Standard Model-like Higgs branching ratios, in addition to null searches for the new resonances in the model. We also perform a detailed comparison with the Minimal Composite Higgs Model, finding that there is in general little difference between the fine-tuning expected in the two scenarios, even after measurements at a high-luminosity, 1 TeV linear collider. Finally, we briefly consider the relationship between fine-tuning and the ability of the extra scalar in the NMCHM model to act as a dark matter candidate, finding that the realisation of a Z2 symmetry that stabilises the scalar is amongst the most natural solutions in the parameter space, regardless of future collider measurements.


Beyond Standard Model Technicolor and Composite Models Effective Field Theories Global Symmetries 


Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.


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Copyright information

© The Author(s) 2019

Authors and Affiliations

  1. 1.ARC Centre of Excellence for Particle Physics at the Terascale, Department of PhysicsUniversity of AdelaideAdelaideAustralia

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