Progress Towards a Muonium Gravity Experiment

TL;DR

This paper discusses progress towards measuring antimatter gravity using muonium, proposing a novel interferometer setup that could achieve high-precision results and potentially reveal new physics about gravity and antimatter.

Contribution

It introduces a new muonium beam and a precision atom interferometer design capable of measuring antimatter gravity with unprecedented accuracy.

Findings

Feasibility of a muonium interferometer with picometer alignment.

Potential to measure antimatter gravity to 1% accuracy.

First possible measurement of leptonic matter's gravitational acceleration.

Abstract

The gravitational acceleration of antimatter, $\bar g$, has yet to be directly measured but could change our understanding of gravity, the Universe, and the possibility of a fifth force. Three avenues are apparent for such a measurement: antihydrogen, positronium, and muonium, the last requiring a precision atom interferometer and benefiting from a novel muonium beam under development. The interferometer and its few-picometer alignment and calibration systems appear to be feasible. With 100 nm grating pitch, measurements of $\bar g$ to 10%, 1%, or better can be envisioned. This could constitute the first gravitational measurement of leptonic matter, of second-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.