Far out cosmology: muon magnetism (Introduction)

by David Turell , Wednesday, April 07, 2021, 21:10 (1324 days ago) @ David Turell

Current measurement doesn't fit theory:

https://www.sciencenews.org/article/muon-physics-standard-model-particles

"In a painstakingly precise experiment, muons’ gyrations within a magnetic field seem to defy predictions of the standard model of particle physics, which describes known fundamental particles and forces. The result strengthens earlier evidence that muons, the heavy kin of electrons, behave unexpectedly.

“'It’s a very big deal,” says theoretical physicist Bhupal Dev of Washington University in St. Louis. “This could be the long-awaited sign of new physics that we’ve all hoped for.”

"Muons’ misbehavior could point to the existence of new types of particles that alter muons’ magnetic properties. Muons behave like tiny magnets, each with a north and south pole. The strength of that magnet is tweaked by transient quantum particles that constantly flit into and out of existence, adjusting the muon’s magnetism by an amount known as the muon magnetic anomaly. Physicists can predict the value of the magnetic anomaly by considering the contributions of all known particles. If any fundamental particles are in hiding, their additional effects on the magnetic anomaly could give them away.

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"A previous measurement of this type, from an experiment completed in 2001 at Brookhaven National Laboratory in Upton, N.Y., also seemed to disagree with theoretical predictions (SN: 2/15/01). When the new result is combined with the earlier discrepancy, the measurement diverges from the prediction by a statistical measure of 4.2 sigma — tantalizingly close to the typical five-sigma benchmark for claiming a discovery. “We have to wait for more data from the Fermilab experiment to really be convinced that this is a real discovery, but it is becoming more and more interesting,” says theoretical physicist Carlos Wagner of the University of Chicago."

Comment: Wow!!! We have to patiently wait.