Testing for Lorentz Violation: Constraints on Standard-Model Extension Parameters via Lunar Laser Ranging

TL;DR

This paper uses Lunar Laser Ranging data to set new constraints on potential violations of Lorentz invariance within the Standard-Model Extension framework, finding no evidence for such violations at extremely precise levels.

Contribution

It provides the first constraints on SME parameters from LLR data, improving bounds on Lorentz violation in the gravitational sector.

Findings

No evidence for Lorentz violation at 10^{-6} to 10^{-11} levels.

Derived six observational constraints on SME parameters.

Enhanced precision in testing fundamental symmetries using lunar data.

Abstract

We present constraints on violations of Lorentz Invariance based on Lunar Laser Ranging (LLR) data. LLR measures the Earth-Moon separation by timing the round-trip travel of light between the two bodies, and is currently accurate to a few centimeters (parts in $10^{11}$ of the total distance). By analyzing archival LLR data under the Standard-Model Extension (SME) framework, we derived six observational constraints on dimensionless SME parameters that describe potential Lorentz-violation. We found no evidence for Lorentz violation at the $10^{-6}$ to $10^{-11}$ level in these parameters.