Muon precession differs from SM prediction

[Genady]

Quote

The new findings, building on data released in 2021, continue to hint at some mysterious factor at play as the researchers try to sort out the discrepancy between the theoretical prediction and the actual experimental results.

"We are looking for an indication that the muon is interacting with something that we do not know about. It could be anything: new particles, new forces, new dimensions, new features of space-time, anything," said Brendan Casey, a senior scientist at Fermilab and one of the authors of a research paper on the findings published in the journal Physical Review Letters.

The odd behavior of a subatomic particle may shake up physics (msn.com)

[studiot]

See also the longer BBC science article.

https://www.bbc.co.uk/news/science-environment-66407099

[exchemist]

1 hour ago, Genady said:

The odd behavior of a subatomic particle may shake up physics (msn.com)

There's a bit more information here: https://www.ucl.ac.uk/news/2023/aug/new-measurement-particle-wobble-hints-new-physics

Seems it all revolves (haha) around the g-factor for muons, which, by making them precess in a magnetic field, has been found to be 0.2ppm (!) stronger than predicted by the Standard Model. So a technical tour de force in terms of measurement and a very tiny difference, which nevertheless is said to be statistically significant, at the 5σ level. This is a replication of earlier results, but with more data behind it.  

[Genady]

3 minutes ago, exchemist said:

There's a bit more information here: https://www.ucl.ac.uk/news/2023/aug/new-measurement-particle-wobble-hints-new-physics

Seems it all revolves (haha) around the g-factor for muons, which, by making them precess in a magnetic field, has been found to be 0.2ppm (!) stronger than predicted by the Standard Model. So a technical tour de force in terms of measurement and a very tiny difference, which nevertheless is said to be statistically significant, at the 5σ level. This is a replication of earlier results, but with more data behind it.  

Perhaps it is not a BIG ANNOUNCEMENT yet because of the 5σ. The golden standard there is 6σ, AFAIK.

[TheVat]

I've heard some fields of science see five sigma as the gold standard, where the chance of that result being random would be one in a million.   But you read of CERN experiments where at least six sigma is needed to be reliable.  Six sigma would be something like one in a half billion.  It would be good to see the SM get shaken up a little.

[Genady]

In some fields, it is one in twenty. E.g., biology.