Table-top precision measurements to test fundamental physics: Measurements of the proton charge radius, the fine-structure constant and the electron electric dipole moment (Prof. Eric Hessels)

Table-top precision measurements to test fundamental physics: Measurements of the proton charge radius, the fine-structure constant and the electron electric dipole moment

Date: May 14, 2019
Time: 02:30 PM (Local Time Germany)
Speaker: Prof. Eric Hessels
York University, Toronto, Ontario, Canada
Location: Max Planck Institute of Quantum Optics
Room: Herbert Walther Lecture Hall

Fundamental physics (including physics beyond the Standard Model) can be tested using table-top precision measurements. The talk will describe measurements of the size of the proton, the fine-structure constant and the electric dipole moment of the electron. Two recently completed measurements will be described.

For the first measurement, the n=2 Lamb shift of atomic hydrogen is measured, allowing for a new determination of the charge radius of the proton. This determination is crucial to resolving the eight-year-old proton radius puzzle, in which it appeared that the proton radius took on a different value when measured with muons compared to measurements using electrons. The second measurement is of the n=2 triplet P fine structure of atomic helium, and this work is part of a program to obtain a new determination of the fine-structure constant. Both of these measurements use a new measurements technique: Frequency offset separated oscillatory fields. Finally, a new major effort (EDM^3) is starting at York University to measure the electron electric dipole moment using polar molecules embedded into inert-gas solids. This measurement will test for T violation and will probe physics up to the PeV energy scale.