A minimal extension of the standard model (SM) with a single new mass scale and providing a complete and consistent picture of particle physics and cosmology up to the Planck scale is presented. We add to the SM three right-handed SM-singlet neutrinos, a new vectorlike color triplet fermion, and a complex SM-singlet scalar σ that stabilizes the Higgs potential and whose vacuum expectation value at ̃1 011 GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously. Primordial inflation is produced by a combination of σ (nonminimally coupled to the scalar curvature) and the SM Higgs boson. Baryogenesis proceeds via thermal leptogenesis. At low energies, the model reduces to the SM, augmented by seesaw-generated neutrino masses, plus the axion, which solves the strong C P problem and accounts for the dark matter in the Universe. The model predicts a minimum value of the tensor-to-scalar ratio r ≃0.004 , running of the scalar spectral index α ≃-7 × 10-4, the axion mass mÃ100 μ eV , and cosmic axion background radiation corresponding to an increase of the effective number of relativistic neutrinos of ̃0.03 . It can be probed decisively by the next generation of cosmic microwave background and axion dark matter experiments.
Physical Review Letters
- Pub Date:
- February 2017
- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Theory
- 7 pages, 2 figures