
New Baryons Discovered at CERN - 0xbadf00d
http://lhcb-public.web.cern.ch/lhcb-public/Welcome.html#Xic
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gus_massa
The interesting part if you are not interested in the business as usual part
of particle physics is:

> _10 March 2020: B0 → K_ μ+ μ-: more data confirm old puzzle.*

> _Compared with the previous LHCb results, the overall tension with the
> Standard Model (SM) is observed to mildly increase._

> _However, the global fit to several angular observables shows that the
> overall tension with the SM increases from 3.0 to 3.3σ._

[Note that the "increase" in the second quote and the "increase" in the third
quote are in different comparisons.]

The idea is that the transformation in the experiment is actually B0 →
<something> → K* μ+ μ- , where there are many known versions of <something>.
But they got a weird result, so there "must" be some unknown versions of
<something>.

This is 3σ, that means that a random fluke has less than .3% of probability of
producing a similar looking weird data. The problem is that they (and other
groups) are running hundred of experiments, so there is a chance that this is
just good/bad luck instead of a unknown <something>.

A 3σ is unusual enough to remember, and to try to explain it with new
theories, but don't get to attached to a 3σ resonance because they may fade
away.

