Description: In 1950 Purcell and Ramsey suggested that the electron might have a CP-violating electric dipole moment (e-EDM) proportional to its spin angular momentum. This possibility initiated an ongoing hunt for the e-EDM that has been spurred on by the recognition of the importance of CP-violation to the formation of a matter-dominated universe as well as a difference in magnitude of the Supersymmetric and Standard Model prediction for its value. The current limit on the e-EDM is 1.6Eâ27 eÂ·cm as determined in a Ramsey beam resonance study of the Tl atom. The PbF molecule provides a unique opportunity to measure the e-EDM. The moleculeâs odd electron, heavy mass, and large internal field combine to give it an intrinsic sensitivity to an e-EDM that is over three orders of magnitude bigger than that of the Tl atom. In addition to this increased intrinsic sensitivity, the ground state of the PbF molecule allows for a "magic" electric field at which the magnetic moment vanishes. All of these advantages create an opportunity to significantly lower the current limit on the e-EDM. These advantages can only be realized if an intense source of ground-state PbF molecules can be created and detected with high efficiency. The scope of this project is to (1) create a rotationally cold molecular beam source of PbF, (2) achieve a continuous ionization scheme for sensitive state selective detection of the PbF molecule.
Date: April 8, 2011
Creator: Shafer-Ray, Neil
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department