Antimatter Gravity and Antihydrogen Production

Certain modern theories of gravity predict that antimatter will fall differently than matter in the Earth’s gravitational field. However, no experimental tests of gravity on antimatter exist and all conclusions drawn from experiments on matter depend, at some level, on a specific model. We have proposed a direct measurement that would compare the gravitational acceleration of antiprotons to that of negatively charged hydrogen ions. Substantial progress towards the development of this experiment has been achieved. Based on our work a number of alternative proposals for measuring “g” on both charged and neutral antimatter have been made. We summarize the present Email: [email protected]; [email protected]; [email protected] status of our experiment and also discuss the steps that would be necessary to produce antihydrogen in an environment suitable for gravity measurements.