Using stochastic acceleration to place experimental limits on the charge   of antihydrogen
  Assuming hydrogen is charge neutral, CPT invariance demands that antihydrogen also be charge neutral. Quantum anomaly cancellation also demands that antihydrogen be charge neutral. Standard techniques based on measurements of macroscopic quantities of atoms cannot be used to measure the charge of antihydrogen. In this paper, we describe how the application of randomly oscillating electric fields to a sample of trapped antihydrogen atoms, a form of stochastic acceleration, can be used to place experimental limits on this charge. 
M. Baquero-Ruiz and A. E. Charman and J. Fajans and A. Little and A.   Povilus and F. Robicheaux and J.S. Wurtele and A. I. ...
physics.atom-ph