A mysterious experiment hinted at an unknown force in physics — but the real answer may be simpler - AlterNet

This is a large-scale collaboration of physicists who have been trying to see if the older theoretical prediction was incorrect.

My team's theoretical prediction is different from the original theory and matches both the old experimental evidence and the new Fermilab data.

The strength and orientation of this magnetic field is called the magnetic moment.

Last is the strong interaction, the force that holds the protons and neutrons in an atom's nucleus together.

All interactions of the Standard Model contribute to the muon's magnetic moment and each do so in multiple different ways.

Physicists very precisely know how electromagnetism and the weak interaction do so, but determining how the strong interaction contributes to the muon's magnetic field has proven to be incredibly hard to do.

The magnetic field of the muon has proven incredibly hard to predict.

Of all of the effects that the strong interaction has on the muon's magnetic moment, the largest and also hardest to calculate with the necessary precision is called the Leading Order Hadronic Vacuum Polarization.

They would collect data from collisions between electrons and positrons – the opposite of electrons – and use it to calculate the strong interaction's contribution to the muon's magnetic moment.

This calculation of the magnetic moment is what experimental physicists have been testing for decades.

Until April 7, 2021, the most precise experimental result was 15 years old.

For this measurement, at Brookhaven National Laboratory, researchers created muons in a particle accelerator and then watched how they moved through a magnetic field using a giant, 50-foot-wide (15-meter) electromagnet.

By measuring how muons moved and decayed, they were able to directly measure the muon's magnetic moment.

It came as quite the surprise when Broohaven's 2006 direct measurement of the muon's magnetic moment was larger than it should have been according to theory.

Faced with this discrepancy, there were three options: Either the theoretical prediction was incorrect, the experiment was incorrect or, as many physicists believed, this was a sign of an unknown force of nature.

Our team of physicists took the most basic underlying equations of the strong interaction, put the equations on an space-time grid and solved as many of them as possible at once.

Similarly, we placed the strong interaction equation on a space-time grid.

Our team put the strong interaction forces on a grid and looked for the evolution of these fields?

In this metaphor, we used billions of airplanes to calculate the most precise magnetic moment we could using millions of computer processing hours at multiple supercomputer centers in Europe?

Our new approach produces an estimate of the strength of the muon's magnetic field that closely matches the experimental value measured by the Brookhaven scientists.

At Fermilab, physicists have been continuing the experiment that was done at Brookhaven to get a more precise experimental measurement of the muon's magnetic moment.

The new theoretical prediction made by my colleagues and me matches with these experimental results

One mystery remains though: the gap between the original prediction and our new theoretical result