Holographic composite Higgs model building: soft breaking, maximal symmetry, and the Higgs mass

bstract We study the emergence and phenomenological consequences of recently proposed new structures, namely soft breaking of the Higgs shift symmetry and ‘maximal symmetry’ of the composite sector, in holographic realizations of composite Higgs models. For the former, we show that soft breaking can also successfully be implemented in a full 5D warped model, where symmetry-restoring universal boundary conditions for the fermion fields allow to break the problematic connection between a realistically light Higgs and anomalously light top partners. For the latter, we demonstrate that the minimal incarnation of maximal symmetry in the holographic dual leads to a sharp prediction of m h ≈ 197 GeV for f = 800 GeV. However, a viable implementation is possible with sizable negative gauge brane kinetic terms, allowing for the observed m h = 125 GeV. Overall, both approaches offer promising directions to improve the naturalness also of holographic realizations of composite Higgs models.