Ethan Siegel completely misses the point. No one would care about the most recent measurement if it would be on its own. But we have something like 10 measurements of b->s mu mu coupling, and they all show a deviation in the same direction. A lower number of muons than expected in the low q range, and with a different than expected angular distribution. The combined significance is much larger than the significance of the individual measurements.
I summarized the more recent measurements here
, but there are also older measurements from the B-factories showing a similar trend.
With the 2015 and 2016 data recorded already, we should know more in about a year.
A technical error in the article:
But a closer inspection of the latest data shows that the statistical significance is only about 2.4 and 2.5 sigma, respectively, at the two energies measured. This is about a 1.5% chance of a fluke individually, or about 3.7-sigma significance (0.023% chance of a fluke) combined
I have no idea how he gets 3.7 sigma. Even with 100% uncorrelated systematics and with the theory predictions that give the largest discrepancies we only get sqrt(2.4^2 + 2.5^2) = 3.5 sigma. But the systematics are correlated, leading to a lower significance.
John Ellis answers his own question, by the way:
Where is Particle Physics Going?
The answer to the question in the title is: in search of new physics beyond the Standard Model, for which there are many motivations, including the likely instability of the electroweak vacuum, dark matter, the origin of matter, the masses of neutrinos, the naturalness of the hierarchy of mass scales, cosmological inflation and the search for quantum gravity. So far, however, there are no clear indications about the theoretical solutions to these problems, nor the experimental strategies to resolve them. It makes sense now to prepare various projects for possible future accelerators, so as to be ready for decisions when the physics outlook becomes clearer. Paraphrasing George Harrison, "If you don't yet know where you're going, any road may take you there."