Phenomenology 2016 Symposium

The spontaneous Z2 breaking Twin Higgs

10 May 2016, 15:00

15m

G31 (Benedum Hall)

parallel talk BSM Higgs II

Speaker

Hugues Beauchesne (Carleton University)

Description

The Twin Higgs model seeks to address the little hierarchy problem by making the Higgs a pseudo-Goldstone of a global $SU(4)$ symmetry that is spontaneously broken to $SU(3)$. Gauge and Yukawa couplings, which explicitly break $SU(4)$, enjoy a discrete $Z_2$ symmetry that accidentally maintains $SU(4)$ at the quadratic level and therefore keeps the Higgs light. However, making the Twin Higgs phenomenologically viable requires introducing a soft $Z_2$ breaking and tuning it against the $SU(4)$ breaking. We propose a model to alleviate this tuning, without the need for an explicit $Z_2$ breaking sector. The model consists of two $SU(4)$ fundamental Higgses, one whose vacuum preserves $Z_2$ and one whose vacuum breaks it. As the interactions between the two Higgses are turned on, the $Z_2$ breaking is transmitted from the broken to the unbroken sector and a small hierarchy of vevs is naturally produced. The presence of an effective tadpole and feedback between the two Higgses lead to a sizable improvement of the tuning. The resulting Higgs boson is naturally very Standard Model like.

Presentation materials

Beauchesne_pheno_2016_2.pdf