Little Hierarchy and Induced EWSB in pNGB Higgs Models.
Kiel Howe (Fermilab)

The scale of electroweak symmetry breaking (EWSB) can be protected if the Higgs is a pseudo-Nambu Goldstone Boson (pNGB) of a global symmetry larger than the Standard Model gauge group. The global-symmetry breaking implied by the Standard Model interactions and current direct experimental limits gives a minimal tuning of the weak scale to a degree of ~20%. However, this little hierarchy problem is exacerbated in many concrete models, where generating a Higgs mass of 125 GeV requires a stronger breaking of the shift symmetry and leads to tuning a degree worse than ~1%. If the low energy structure of the Higgs potential is extended, this extra tuning can be avoided. We describe one such modification, "Induced Electroweak-Symmetry Breaking", and its application to the minimal composite Higgs models (MCHM) and the Twin Higgs.