Tadpole- induced electroweak symmetry breaking and pNGB Higgs models

We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, vH << fH. When the pNGB potential is generated radiatively, this hierarchy requires fine- tuning to a degree of at least similar to v(H)(2) / f(H)(2). We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale fS << vH, this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Composite Higgs models based on SO(5)/ SO(4) and in Twin Higgs models. For the Twin case, the result is a fully natural model with fH similar to 1TeV and the lightest colored top partners at 2TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale fH, with a natural hierarchy fS << vH << fH similar to TeV. The framework predicts modified Higgs coupling as well as new Higgs and vector states at LHC13.