Concepts like the Higgs boson and dark energy don’t fully integrate with the Standard Model, and the Muon g−2 might eventually help us understand why.
The roots of the Muon g−2 experiment go back to work done at CERN in the late 1950s.Whatever is causing muons to misbehave in Muon g−2 could be a fifth force, but we don’t know what it is.