Now, the Advanced Cold Molecule Electron Electric Dipole Moment, or ACME, search, based at Harvard University, has probed the electron’s EDM with the most precision ever — and still found no sign of smooshing, the team reports online October 17 in Nature.
The finding improves the team’s last best measurement (SN Online: 12/19/13) by a factor of 10 to find an EDM of 10-29 electron charge centimeters. That’s as round as if the electron were a sphere the size of the Earth, and you shaved less than two nanometers off the North Pole and pasted it onto the South Pole, says Yale University physicist David DeMille, a member of the ACME team.
This improves upon the previous measurement that I mentioned a year ago. Looks like if any theory predicts the possible structure of an electron, they have some severe constraints to overcome.