2021/06/23 by David Curtin, Shayne Gryba, Dan Hooper +2
Computer Science · Physics and Astronomy · #Annihilation #Astrophysics and Cosmic Phenomena #Axion #Baryogenesis #Computational Physics and Python Applications #Dark matter #Geometry #Higgs boson #Nuclear physics #Parameter space #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Scalar (mathematics) #WIMP #Yukawa potential #hep-ph
paper · pdf · doi:10.1103/physrevd.105.035033
12 pages, 3 figures
arxiv created 2021/06/23 · openalex created_date 2021/07/05 · openalex publication_date 2022/02/25 · arxiv updated 2022/03/14 · openalex updated_date 2026/08/06
In Twin Higgs models which contain the minimal particle content required to address the little hierarchy problem (i.e. fraternal models), the twin tau has been identified as a promising candidate for dark matter. In this class of scenarios, however, the elastic scattering cross section of the twin tau with nuclei exceeds the bounds from XENON1T and other recent direct detection experiments. In this paper, we propose a modification to the Fraternal Twin Higgs scenario that we call ℤ2FTH, incorporating visible and twin hypercharged scalars (with Y = 2) which break twin electromagnetism. This leads to new mass terms for the twin tau that are unrelated to its Yukawa coupling, as well as additional annihilation channels via the massive twin photon. We show that these features make it possible for the right-handed twin tau to freeze out with an acceptable thermal relic abundance while scattering with nuclei at a rate that is well below existing constraints. Nonetheless, large portions of the currently viable parameter space in this model are within the reach of planned direct detection experiments. The prospects for indirect detection using gamma rays and cosmic-ray antiprotons are also promising in this model. Furthermore, if the twin neutrino is light, the predicted deviation of ΔNeff ≈ 0.1 would be within reach of Stage 4 CMB experiments. Finally, the high luminosity LHC should be able to probe the entire parameter space of the ℤ2FTH model through charged scalar searches. We also discuss how searches for long-lived particles are starting to constrain Fraternal Twin Higgs models.