(ORDO NEWS) — The Standard Model of particle physics is our best guess at what the blueprints of matter look like. Of all his predictions, none is as accurate as the magnetic moment of the electron.
Not only is it accurately predicted, but it is one of the most accurately measured properties of any particle. And while the two values are close, they don’t completely overlap, giving tantalizing hints of new physics.
Approaching the exact value of an electron’s magnetic moment in other words, how strongly an electron behaves like a tiny magnet may one day open up a deeper understanding of the building blocks of physics and how they interact.
Now physicists at Harvard and Northwestern have pushed the limits of that precision even further. Their recent experiments gave a value accurate to 0.13 out of 1 trillion.
“The new value is 2.2 times more accurate and consistent with the one that has existed for 14 years,” the researchers write from their published paper.
“Our definition and calculation of the Standard Model is accurate enough for a test that is 10 times more accurate.”
To get a new value for the electron’s magnetic moment, the research team placed one electron in a well-controlled chamber known as a Penning trap.
After cooling the chamber to near absolute zero, the team was able to use the magnetic field to measure the “quantum jumps” of the electron. between energy levels without affecting its quantum state and without distorting observations.
The Standard Model equations allow us to calculate what is called the fine structure constant. Roughly equivalent to 1/137, it underlies the electromagnetic force that binds atoms, making it very important in physics.
These same equations predict the electron’s magnetic moment with such impressive accuracy that measuring it in the laboratory has become the ultimate test of the Standard Model’s ability to reflect reality.
For some time, measurements of the electron’s magnetic moment remained slightly larger than what the Standard Model predicts for a charged point particle, producing a tempting anomaly that needs to be resolved.
These new results have a margin of error ten times smaller than this discrepancy, clearly pointing to unknown physics.
Fine-tuning both predictions and experimental results can yield values that hint at the existence of new particles or types of interactions that we don’t yet know about. p>
The researchers already have ideas on how to improve the measurement represented as μ/μB (comparison of the value with the Bohr magneton) even further.
This brings us closer to the final completion of the Standard Model of particle physics.
“Significant improvements in µ/µB accuracy now seem possible given the demonstration of more stable hardware, improved statistics, and a better understanding of uncertainty,” the researchers write.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.