Measuring Antimatter Gravity with Muonium

TL;DR

This paper proposes a novel atom interferometry method using muonium to measure antimatter's gravitational acceleration, potentially marking the first such measurement for leptonic matter.

Contribution

It introduces a new experimental approach employing a low-velocity muonium beam and nanofabricated gratings for precise gravity measurement of antimatter.

Findings

Potential to measure antimatter gravity within months of beam time

First proposed measurement of leptonic antimatter gravity

Use of nanofabricated gratings for high-precision interferometry

Abstract

We consider a measurement of the gravitational acceleration of antimatter, gbar, using muonium. A monoenergetic, low-velocity, horizontal muonium beam will be formed from a surface-muon beam using a novel technique and directed at an atom interferometer. The measurement requires a precision three-grating interferometer: the first grating pair creates an interference pattern which is analyzed by scanning the third grating vertically using piezo actuators. State-of-the-art nanofabrication can produce the needed membrane grating structure in silicon nitride or ultrananoscrystalline diamond. With 100 nm grating pitch, a 10% measurement of gbar can be made using some months of surface-muon beam time. This will be the first gravitational measurement of leptonic matter, of 2nd-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.