The Big Theoretical Physics Problem At The Center Of The ‘Muon g-2’ Puzzle
“Assuming that the experimental results from the Muon g-2 collaboration hold up — and there’s every reason to believe they will, including the solid agreement with the earlier Brookhaven results — all eyes will turn towards the theorists. We have two different ways of calculating the expected value of the muon’s spin magnetic moment, where one agrees with the experimental values (within the errors) and the other does not.
Will the Lattice QCD groups all converge on the same answer, and demonstrate that not only do they know what they’re doing, but that there’s no anomaly after all? Or will Lattice QCD methods reveal a disagreement with the experimental values, the same way that they presently disagree with the other theoretical method we have that presently disagrees so significantly with the experimental values we have: of using experimental inputs instead of theoretical calculations?
It’s far too early to say, but until we have a resolution to this important theoretical issue, we won’t know what it is that’s broken: the Standard Model, or the way we’re presently calculating the same quantities we’re measuring to unparalleled precisions.”
The initial reactions are all in. Now, it’s time for a next-level look at the muon g-2 puzzle. What will the resolution be? It might not have anything to do with breaking the Standard Model.
