Speaker
Daniel Kaplan
(Illinois Institute of Technology)
Description
The gravitational acceleration of antimatter (gbar) 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---a mu+ e- atom. The muonium measurement requires a novel monoenergetic, low-velocity, horizontal muonium beam (under development at PSI) 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 gbar 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.
Primary author
Daniel Kaplan
(Illinois Institute of Technology)
Co-authors
Prof.
Derrick Mancini
(Illinois Institute of Technology)
Dr
James phillips
(Harvard-Smithsonian Center for Astrophysics)
Klaus Kirch
(PSI)
Dr
Thomas Phillips
(Illinois Institute of Technology)
Dr
Tom Roberts
(Illinois Institute of Technology)
