>>12943056It's elaborated much better in the nature article, but the "standard model" prediction wasn't historically done by raw perturbative calculation a la QED (because QCD can't be calculated perturbatively), but rather using a "dispersion relation," which I'll admit I don't really understand.
It turns out when you use ab initio lattice QCD calculations, which are just starting to get to the level that we can calculate terms such as this, they agree more with the measured values than with the previous theoretical values. So it seems there's no discrepancy.
