Electroweak baryogenesis from a dark sector
Cline, J. M., Kainulainen, K., & Tucker-Smith, D. (2017). Electroweak baryogenesis from a dark sector. Physical Review D, 95 (11), 115006. doi:10.1103/PhysRevD.95.115006
Published inPhysical Review D
© the Authors, 2017. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license.
Adding an extra singlet scalar S to the Higgs sector can provide a barrier at tree level between a false vacuum with restored electroweak symmetry and the true one. This has been demonstrated to readily give a strong phase transition as required for electroweak baryogenesis. We show that with the addition of a fermionic dark matter particle χ coupling to S, a simple UV-complete model can realize successful electroweak baryogenesis. The dark matter gets a CP asymmetry that is transferred to the standard model through a CP portal interaction, which we take to be a coupling of χ to τ leptons and an inert Higgs doublet. The CP asymmetry induced in left-handed τ leptons biases sphalerons to produce the baryon asymmetry. The model has promising discovery potential at the LHC, while robustly providing a large enough baryon asymmetry and correct dark matter relic density with reasonable values of the couplings.