Progress towards a more sensitive measurement of the electron electric dipole moment with YbF
File(s)
Author(s)
Devlin, Jack Alexander
Type
Thesis
Abstract
The electron is predicted to have a small electric dipole moment (eEDM), although so far no one has been able to measure this experimentally. The size of the eEDM is strongly connected to how badly time-reversal (T) symmetry is broken by nature. The Standard Model of particle physics, which has a small amount of T violation, predicts an unmeasurably tiny eEDM: de < 10^(-38) e cm. However, it is suggested that there should be additional T-violating processes to account for the matter-antimatter asymmetry in the universe. These could lead to a detectable eEDM near to the current limit |de|< 8.7*10^(-29) e cm (90\% confidence).
Ramsey spectroscopy on paramagnetic, polar molecules has proved a very effective method for measuring eEDMs. In this thesis I explain the progress that has been made towards using ytterbium fluoride (YbF) for a new, improved measurement of the eEDM. I discuss the current operation of the experiment, and the systematic effects connected with the experiment. The statistical uncertainty of the experiment in analysed, and shown to be dominated by photon counting statistics. Then, a list of improvements to the machine are described, and simulated using rate equations and the optical Bloch equations. Taken together, these improvements enhance the sensitivity of the experiment by a factor of eleven, thus, it can be used in the near future to make a world-leading measurement of the electron EDM.
Ramsey spectroscopy on paramagnetic, polar molecules has proved a very effective method for measuring eEDMs. In this thesis I explain the progress that has been made towards using ytterbium fluoride (YbF) for a new, improved measurement of the eEDM. I discuss the current operation of the experiment, and the systematic effects connected with the experiment. The statistical uncertainty of the experiment in analysed, and shown to be dominated by photon counting statistics. Then, a list of improvements to the machine are described, and simulated using rate equations and the optical Bloch equations. Taken together, these improvements enhance the sensitivity of the experiment by a factor of eleven, thus, it can be used in the near future to make a world-leading measurement of the electron EDM.
Version
Open Access
Date Issued
2015-07
Date Awarded
2015-11
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Hinds, Ed
Hudson, Jony
Sponsor
Engineering and Physical Sciences Research Council
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)