Measurement of the electron's electric dipole moment using YbF molecules: methods and data analysis

Abstract

We recently reported a new measurement of the electron's electric dipole\nmoment using YbF molecules [Nature 473, 493 (2011)]. Here, we give a more\ndetailed description of the methods used to make this measurement, along with a\nfuller analysis of the data. We show how our methods isolate the electric\ndipole moment from imperfections in the experiment that might mimic it. We\ndescribe the systematic errors that we discovered, and the small corrections\nthat we made to account for these. By making a set of additional measurements\nwith greatly exaggerated experimental imperfections, we find upper bounds on\npossible uncorrected systematic errors which we use to determine the systematic\nuncertainty in the measurement. We also calculate the size of some systematic\neffects that have been important in previous electric dipole moment\nmeasurements, such as the motional magnetic field effect and the geometric\nphase, and show them to be negligibly small in the present experiment. Our\nresult is consistent with an electric dipole moment of zero, so we provide\nupper bounds to its size at various confidence levels. Finally, we review the\nprospects for future improvements in the precision of the experiment.\n