Measuring g with a beam of antihydrogen

AEgIS is a physics experiment that takes place at the european laboratory CERN, using the antiprotons delivered by the AD accelerator. AEgIS is a collaboration of physicists from all around the world.
The primary scientific goal of the AEgIS experiment is the direct measurement of the Earth’s gravitational acceleration g on antihydrogen. In the first phase of the experiment, a gravity measurement with 1% precision will be carried out by sending an antihydrogen beam through a classical Moire deflectometer coupled to a position sensitive detector. This will represent the first direct measurement of a gravitational effect on an antimatter system. aegis.web.cern.ch

Why We Already Know that Antihydrogen is Almost Certainly NOT Going to Fall “Up”

Scott Menary
The ALPHA collaboration (of which I am a member) has made great strides recently in trapping antihydrogen[1, 2] and starting down the path of making spectroscopic measurements[3].
The primary goal of the experiment is to test CPT invariance but there is also interest in testing another fundamental issue – the gravitational interaction between matter and antimatter (the so-called question of “antigravity”).
As well as the other antihydrogen trapping experiments – ASACUSA[4] and ATRAP[5] – there is also a new experiment in the Antiproton Decelerator hall at CERN called AEGIS[6] which is dedicated to testing the gravitional interaction between antihydrogen and the Earth. It was claimed in [7] that there “is no compelling evidence or theoretical reason to rule out such a difference (i.e., between g and ¯g) at the 1% level.
I argue in this short paper that bending of light by the sun provides a more stringent limit than this2….

Read more: http://arxiv.org/pdf/1207.7358v1.pdf