Review of Neutral Naturalness

Abstract

The hierarchy between the mass of the Higgs boson and larger mass scales becomes ever more puzzling as experiments push to higher energies. Neutral naturalness is the umbrella term for symmetry-based explanations for these hierarchies whose quark symmetry partners are not charged under the SU (3) c color gauge group of the Standard Model. Though the first manifestations of this idea predate the physics runs of the Large Hadron Collider, since the Higgs discovery this paradigm has grown and developed to include a wide variety of models, connections to intriguing collider signals, various dark matter candidates, intersections with astrophysics and cosmology, motivations for lattice studies, and ties to neutrinos and flavor. In this review we orient the reader within this growing literature and reveal interesting directions for further study.

Electromagnetic Signatures of Mirror Stars

“…Importantly, many theories of beyond-SM (BSM) physics that address various long-standing mysteries in fundamental physics predict the existence of exactly such a dark sector. The most relevant examples are models of neutral naturalness such as the mirror twin Higgs (MTH; Chacko et al 2006Chacko et al , 2017Craig et al 2017), and NNaturalness (Arkani-Hamed et al 2016), both of which solve the electroweak hierarchy problem in a different manner from canonical frameworks like supersymmetry (Martin 1998), making them compatible with null results from the Large Hadron Collider; see reviews by Batell et al (2022) and Craig (2023). The MTH and NNaturalness include at least one complex dark sector related to the SM by a discrete symmetry, thereby predicting the existence of twin protons, twin neutrons, and twin electrons interacting via twin versions of the SM forces, essentially implementing ADM with nuclear interactions.…”