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Newly published results of an international experiment hint at the possibility of new physics governing the laws of nature.

Standard Model

• The Standard Model is a rigorous theory that predicts the behaviour of the building blocks of the universe.
• It lays out the rules for six types of quarks, six leptons, the Higgs boson, three fundamental forces, and how the subatomic particles behave under the influence of electromagnetic forces.
• It is similar to the electron, but 200 times larger, and much more unstable, surviving for a fraction of a second.
• The experiment, called Muon g–2 (g minus two), was conducted at the US Department of Energy’s Fermi National Accelerator Laboratory (Fermilab).

What was this experiment about?

• It measured a quantity relating to the muon, following up a previous experiment at Brookhaven National Laboratory, under the US Department of Energy. Concluded in 2001, the
• Brookhaven experiment came up with results that did not identically match predictions by the Standard Model.
• The Muon g–2 experiment measured this quantity with greater accuracy.
• It sought to find out whether the discrepancy would persist, or whether the new results would be closer to predictions. 

Findings

The results, while diverging from the Standard Model prediction, strongly agree with the Brookhaven results, Fermilab said.

The accepted theoretical values for the muon are:
g-factor: 2.00233183620
anomalous magnetic moment: 0.00116591810

Source: Indian Express