The standard model of particle physics passed one of its strictest tests yet
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Loading... - Benjamin Rogers
- 02 Mar 2023
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Electrons’ magnetism confirms particle physics’ most precise prediction
No one has ever probed a particle more stringently than this.
In a new experiment, scientists measured a magnetic property of the electron more carefully than ever before, making the most precise measurement of any property of an elementary particle, ever. Known as the electron magnetic moment, it’s a measure of the strength of the magnetic field carried by the particle.
That property is predicted by the standard model of particle physics, the theory that describes particles and forces on a subatomic level. In fact, it’s the most precise prediction made by that theory.
By comparing the new ultraprecise measurement and the prediction, scientists gave the theory one of its strictest tests yet. The new measurement agrees with the standard model’s prediction to about 1 part in a trillion, or 0.1 billionths of a percent, physicists report in the February 17 Physical Review Letters.
When a theory makes a prediction at high precision, it’s like a physicist’s Bat Signal, calling out for researchers to test it. “It’s irresistible to some of us,” says physicist Gerald Gabrielse of Northwestern University in Evanston, Ill.
To measure the magnetic moment, Gabrielse and colleagues studied a single electron for months on end, trapping it in a magnetic field and observing how it responded when tweaked with microwaves. The team determined the electron magnetic moment to 0.13 parts per trillion, or 0.000000000013 percent. Read More…
