A Predictive Mirror Twin Higgs with Small ${\mathbf{Z}}_2$ Breaking

Abstract

The twin Higgs mechanism is a solution to the little hierarchy problem in which the top partner is neutral under the Standard Model (SM) gauge group. The simplest mirror twin Higgs (MTH) model -- where a ${\mathbf{Z}}_2$ symmetry copies each SM particle -- has too many relativistic degrees of freedom to be consistent with cosmological observations. We demonstrate that MTH models can have an observationally viable cosmology if the twin mass spectrum leads to twin neutrino decoupling before the SM and twin QCD phase transitions. Our solution requires the twin photon to have a mass of $\sim 20$ MeV and kinetically mix with the SM photon to mediate entropy transfer from the twin sector to the SM. This twin photon can be robustly discovered or excluded by future experiments. Additionally, the residual twin degrees of freedom present in the early Universe in this scenario would be detectable by future observations of the cosmic microwave background.

arXiv comment14+7 pages, 4 figures. v2: published in JHEP with minor revisions (no change to results)

References in corpus (34)

• Big Bang Nucleosynthesis: 2015
• Leptogenesis for Pedestrians
• Measurement of the fine-structure constant as a test of the Standard Model
• Towards a complete theory of thermal leptogenesis in the SM and MSSM
• A facility to Search for Hidden Particles at the CERN SPS: the SHiP physics case
• The Twin Higgs: Natural Electroweak Breaking from Mirror Symmetry
• The effects of He I 10830 on helium abundance determinations
• FASER's Physics Reach for Long-Lived Particles
• Relic neutrino decoupling with flavour oscillations revisited
• A precision calculation of the effective number of cosmological neutrinos
• Standard Model Higgs-Boson Branching Ratios with Uncertainties
• Twin SUSY
• AlterBBN: A program for calculating the BBN abundances of the elements in alternative cosmologies
• A Supersymmetric Twin Higgs
• A Holographic Twin Higgs Model
• Doubling down on naturalness with a supersymmetric twin Higgs
• Cosmology in Mirror Twin Higgs and Neutrino Masses
• Minimal Mirror Twin Higgs
• Cosmological Signals of a Mirror Twin Higgs
• The Fraternal WIMP Miracle
• Effects of non-standard neutrino-electron interactions on relic neutrino decoupling
• Observable signatures of dark photons from supernovae
• The Vector-like Twin Higgs
• Projections for Dark Photon Searches at Mu3e
• Exotic Quarks in Twin Higgs Models
• SUSY Meets Her Twin
• Asymptotically Free Natural SUSY Twin Higgs
• The Heavy Photon Search experiment at Jefferson Laboratory
• The Flavor of the Composite Twin Higgs
• Coscattering/Coannihilation Dark Matter in a Fraternal Twin Higgs Model
• Effective Theory of Flavor for Minimal Mirror Twin Higgs
• Supersymmetric D-term Twin Higgs
• Minimal Non-Abelian Supersymmetric Twin Higgs
• Breaking Mirror Twin Hypercharge

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• Symmetry of Cosmological Observables, and a High Hubble Constant as an Indicator of a Mirror World Dark Sector
• Mirror Twin Higgs Cosmology: Constraints and a Possible Resolution to the $H_0$ and $S_8$ Tensions
• Making the Universe at 20 MeV
• Dark sector searches with the CMS experiment
• Bounds on boosted dark matter from direct detection: The role of energy-dependent cross sections
• Direct Detection of Mirror Matter in Twin Higgs Models
• Scaling Transformations and the Origins of Light Relics Constraints from Cosmic Microwave Background Observations
• Direct Detection of Atomic Dark Matter in White Dwarfs
• Blazar boosted Dark Matter -- direct detection constraints on ${\sigma }_{e\chi }$ : Role of energy dependent cross sections
• Thomson scattering: One rate to rule them all
• Cosmology of the Twin Higgs without explicit ${\mathbb{Z}}_2$ breaking
• First-order phase transitions in Twin Higgs models
• Data-driven study of the implications of anomalous magnetic moments and lepton flavor violating processes of $e$, $\mu$ and $\tau$
• Twin Cogenesis
• Twin Quark Dark Matter From Cogenesis
• Gegenbauer's Twin
• Breaking Mirror Twin Color
• Dark photon portal into mirror world
• Cool dark sector, concordance, and a low ${\sigma }_8$
• Common Origin of Warm Dark Matter and Dark Radiation
• Review of Neutral Naturalness
• Thorne-Żytkow objects with mirror neutron star cores?