ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Michele Redi (CERN)
Title: Axion-Higgs Unification
Date (JST): Wed, Mar 13, 2013, 13:30 - 14:30
Place: Seminar Room A
Related File: 848.pdf
Abstract: I will discuss a unified framework for the Higgs boson and axion both arising from the spontaneous breaking of a non-abelian global symmetry G->H. The Goldstone symmetry of the Higgs is broken by the SM couplings while the axion shift symmetry is only broken by the QCD anomaly. Dark matter determines the decay constant of the Goldstone bosons f ~ 10^{11}GeV so that the electro-weak VEV is obtained by tuning. We present explicit examples in terms of SU(n) and SO(n) gauge theories when fermion masses are generated through bi-inear couplings of SM fermions as in technicolor. Axion-Higgs models can also be realized if SM fields couple linearly as in modern composite Higgs constructions, most simply within the pattern SO(6)/SO(5). We also show that with a large compositeness scale, a 125 GeV Higgs mass may follow from the Goldstone nature of the Higgs.