Repository logo
  • Log In
    Log in via Symplectic to deposit your publication(s).
Repository logo
  • Communities & Collections
  • Research Outputs
  • Statistics
  • Log In
    Log in via Symplectic to deposit your publication(s).
  1. Home
  2. Faculty of Natural Sciences
  3. Physics
  4. Physics PhD theses
  5. An ultracold beam of YbF molecules for measuring the electron’s electric dipole moment
 
  • Details
An ultracold beam of YbF molecules for measuring the electron’s electric dipole moment
File(s)
Swarbrick-S-2023-PhD-Thesis.pdf (34.23 MB)
Thesis
Author(s)
Swarbrick, Simon Christopher
Type
Thesis or dissertation
Abstract
The observed matter-antimatter asymmetry of the universe remains unexplained and undiscovered sources of CP violation could yet prove to be its source. The electric dipole moment of leptons, strongly suppressed in the Standard Model, would be a source of CP violation and a sign of new physics. Recent measurements of the electron EDM have already pushed constraints on the energy range for new particles to be discovered beyond the reach of the LHC.

This work focuses on the progress towards an experiment to measure the electron EDM using YbF. A buffer gas-cooled molecular source generates a pulsed beam of YbF molecules travelling at 180 m/s. Employing two-dimensional laser cooling, the transverse temperature of the beam drops below 200μK, significantly increasing its brightness by over two orders of magnitude compared to the uncooled beam. On average, each cooled beam pulse contains approximately 2x10^5 ultracold molecules. A hexapole magnetic lens will guide the molecular beam towards the cooling lasers. Simulations predict that the lens will enhance beam brightness by at least five-fold. Combined with transverse laser cooling, this magnetic lens has the potential to yield a beam three orders of magnitude brighter. This enhancement will enable a measurement of the electron EDM, with a statistical uncertainty of 2.2x10^(-31) e cm. This will represent an improvement of over an order of magnitude compared to the recent record established by JILA. Lastly, a new optical pumping scheme has been developed to transfer molecules from their laser cooling state to the absolute ground state of YbF, preparing for electron EDM measurement. This work lays the foundation for a high-precision measurement of the electron EDM using YbF.
Version
Open Access
Date Issued
2023-05
Date Awarded
2023-12
URI
http://hdl.handle.net/10044/1/108821
DOI
https://doi.org/10.25560/108821
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
https://creativecommons.org/licenses/by-nc/4.0/
Advisor
Tarbutt, Michael
Sauer, Ben
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)
About
Spiral Depositing with Spiral Publishing with Spiral Symplectic
Contact us
Open access team Report an issue
Other Services
Scholarly Communications Library Services
logo

Imperial College London

South Kensington Campus

London SW7 2AZ, UK

tel: +44 (0)20 7589 5111

Accessibility Modern slavery statement Cookie Policy

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science

  • Cookie settings
  • Privacy policy
  • End User Agreement
  • Send Feedback