# Lorentz Symmetry Violations from Matter-Gravity Couplings with Lunar Laser Ranging

## TL;DR

This paper uses lunar laser ranging to test Lorentz symmetry violations within the Standard-Model Extension framework, providing the first simultaneous measurements in matter and gravity sectors, and sets new stringent constraints.

## Contribution

It presents the first direct experimental measurement of SME coefficients in both matter and gravitational sectors using lunar laser ranging data, improving constraints significantly.

## Key findings

- No deviation from general relativity detected
- Set new constraints on Lorentz symmetry violations
- Improved previous bounds by up to three orders of magnitude

## Abstract

The standard-model extension (SME) is an effective field theory framework aiming at parametrizing any violation to the Lorentz symmetry (LS) in all sectors of physics. In this Letter, we report the first direct experimental measurement of SME coefficients performed simultaneously within two sectors of the SME framework using lunar laser ranging observations. We consider the pure gravitational sector and the classical point-mass limit in the matter sector of the minimal SME. We report no deviation from general relativity and put new realistic stringent constraints on LS violations improving up to 3 orders of magnitude previous estimations.