Equivalence Principle and the Gauge Hierarchy Problem

TL;DR

This paper proposes a solution to the gauge hierarchy problem using scalar-tensor theories of gravity, avoiding extra dimensions and new strongly coupled physics, by linking the scale splitting to a violation of Einstein's equivalence principle.

Contribution

It introduces a novel approach that connects the gauge hierarchy problem to equivalence principle violation within scalar-tensor gravity frameworks, without requiring extra dimensions.

Findings

The hierarchy problem can be addressed via gravitational sector fine-tuning.

The mechanism does not rely on extra dimensions or strongly coupled new physics.

The scalar field couples only gravitationally to matter.

Abstract

We show that the gauge hierarchy problem can be solved in the framework of scalar-tensor theories of gravity very much in the same way as it is solved in the Randall-Sundrum scenario. Our solution involves a fine-tuning of the gravitational sector. However our mechanism does not require the introduction of extra-dimensions or new physics strongly coupled to the standard model in the low energy regime. We do introduce a new scalar field which is however coupled only gravitationally to regular matter. The physical reason for the splitting between the weak scale and the Planck scale is a violation of the Einstein's equivalence principle.