2016/01/26 by Daniel M. Kaplan, Kaplan, Daniel M, Ephraim Fischbach +15
Engineering · Physics and Astronomy · #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Experiment (hep-ex) #Instrumentation and Detectors (physics.ins-det) #Muon and positron interactions and applications #Noncommutative and Quantum Gravity Theories #Quantum and Classical Electrodynamics
paper · pdf · doi:10.48550/arxiv.1601.07222
openalex publication_date 2016/01/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The gravitational acceleration of antimatter, g, has never been directly measured and could bear importantly on our understanding of gravity, the possible existence of a fifth force, and the nature and early history of the universe. Three avenues appear feasible for such a measurement: antihydrogen, positronium, and muonium. The muonium measurement requires a novel monoenergetic, low-velocity, horizontal muonium beam directed at an atom interferometer. The precision three-grating interferometer can be produced in silicon nitride or ultrananocrystalline diamond using state-of-the-art nanofabrication. The required precision alignment and calibration at the picometer level also appear to be feasible. With 100 nm grating pitch, a 10% measurement of g can be made using some months of surface-muon beam time, and a 1% or better measurement with a correspondingly larger exposure. This could constitute the first gravitational measurement of leptonic matter, of 2nd-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.