Cosmological Implications of a Scale Invariant Standard Model

Abstract

We generalize the standard model of particle physics such it displays global scale invariance. The gravitational action is also suitably modified such that it respects this symmetry. This model is interesting since the cosmological constant term is absent in the action. We find that the scale symmetry is broken by the recently introduced cosmological symmetry breaking mechanism. This simultaneously generates all the dimensionful parameters such as the Newton's gravitational constant, the particle masses and the vacuum or dark energy. We find that in its simplest version the model predicts the Higgs mass to be very small, which is ruled out experimentally. We further generalize the model such that it displays local scale invariance. In this case the Higgs particle disappears from the particle spectrum and instead we find a very massive vector boson. Hence the model gives a consistent description of particle physics phenomenology as well as fits the cosmological dark energy.