Non-minimal quartic inflation in classically conformal U(1)$_X$ extended Standard Model

Understand

We propose quartic inflation with non-minimal gravitational coupling in the context of the classically conformal U(1)_X extension of the SM.

• In this model, the U(1)_X gauge symmetry is radiatively broken through the Coleman-Weinberg (CW) mechanism, by which the U(1)_X gauge boson (Z' boson) and the right-handed neutrinos (RHNs) acquire their masses.
• We consider their masses in the range of O(10 GeV)-O(10 TeV), which are accessible to high energy collider experiments.
• The radiative U(1)_X gauge symmetry breaking also generates a negative mass squared for the SM Higgs doublet, and the electroweak symmetry breaking occurs subsequently.