Fermi scale from quantum gravity scaling solution

TL;DR

This paper proposes that fundamental scale invariance in quantum gravity can predict the ratio between the Fermi scale and the Planck mass, potentially explaining the gauge hierarchy problem.

Contribution

It introduces an analytic scaling solution for quantum gravity that predicts the Fermi to Planck mass ratio without free parameters, linking scale invariance to the gauge hierarchy.

Findings

The Fermi to Planck scale ratio is predicted to be very small.

The solution suggests a connection to a second order electroweak phase transition.

The model provides a potential explanation for the gauge hierarchy problem.

Abstract

Fundamental scale invariance implies the scale invariant standard model. Both the Fermi scale and the Planck mass are given by fields, and their ratio is dictated by a dimensionless cosmon-Higgs coupling. For an ultraviolet fixed point of quantum gravity this coupling is an irrelevant parameter of the renormalization flow and becomes predictable. An analytic scaling solution for quantum gravity admits no free parameter for the mass term of the Higgs boson. If the largest intrinsic mass scale generated by the renormalisation flow away from the fixed point is sufficiently below the Fermi scale, the couplings of the scale invariant standard model are determined by the scaling solution. For a given short distance model remaining valid to infinitely small distances the ratio Fermi scale over Planck mass can be predicted. With reasonable assumptions for an ultraviolet fixed point a numerical solution finds a tiny value for the ratio between the Fermi and Planck scales, very close to a second order quantum electroweak phase transition. This could explain the observed gauge hierarchy.