Testing Planck scale gravity with accelerators

TL;DR

This paper proposes a novel laboratory method using laser Compton scattering at existing and future accelerators to test for quantum gravity effects like space refractivity and birefringence at scales approaching the Planck length.

Contribution

It introduces a new experimental approach to detect quantum gravity effects at sub-Planckian scales using high-energy lepton accelerators.

Findings

Potential sensitivity down to 1E-31m in space refractivity

Existing experimental hints suggest gravity signatures near the Planck scale

Method applicable to current and future accelerator facilities

Abstract

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 1E-35 m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement since the smallest distance accessible in experiment is about 1E-19 m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 1E-31m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data.