Guide to the ACME EDM Experiment
An ongoing series in which I introduce the electron EDM experiment I am working on at Harvard bit by bit, trying as much as possible to avoid technical jargon and making an explanation understandable by a general audience with only high school-level mathematics. Our official website is here.
Note that all content in this blog is solely my own personally writing and does not necessarily represent the views of the entire ACME collaboration. However I have done my best to make the information as accurate as possible.
For a quick introduction to the experiment, read Introducing the ACME EDM Experiment, which explains the gist of what we are doing in ACME by measuring the roundness of the electron.
For an explanation for why the roundness of the electron matters at all, read Why CP Violation Might Explain Everything About the Universe explaining how the electron EDM relates to the problem of baryon asymmetry.
For a more detailed outline of how the experiment works, read A Simple Overview. This includes an explanation for spin precession, the core physical process which allows us to probe the effects of the deformation of the electron.
The following articles are longer, but are useful to fully understand the physics and methods present in the experiment.
- Atomic Structure A tutorial on how energy is “stored” in atoms and molecules. This is the energy we measure carefully when doing the spin precession.
- Differential Measurements to the Extreme The concept of a differential measurement, which defines the fundamental operation of the ACME experiment.
- Symmetries in Physics An explanation of C, P, and T symmetries and how the electron EDM violates CP symmetry, allowing it to be used as a probe for CP violation, which relates to it being able to solve the baryon asymmetry problem.
A Brief History of the Electron’s Shape
In this series, which is quite like no other, you will see me go through 60 years of measurements of the electron electric dipole moment, from 1965 to the present day! I guarantee that there is nothing quite like this on the Web.
- Part 1: Origins. Learn about the three physicists who first made us realize the importance of the electron’s shape: Purcell, Ramsey, and Sandars.
- Part 2: The First “Golden Age”. Sandars and his competitors usher in a rush of activity measuring the electron EDM in the 60s by developing the cesium beam technique.
- Part 3: How My Small College Measured the Electron’s Shape. After a long two-decade drought, a small college in Western Massachusetts resurrects the subject by achieving a massive improvement.
- Part 4: The Ultimate Atomic Beam Experiment. Eugene Commins at Berkeley brings the art of atomic beams to its zenith.