Direct observation of the dead-cone effect in quantum chromodynamics

The scientists did an experiment and showed that their theory about very tiny bits of stuff is what had been predicted by a theory we came up with about 50 years ago.

At a higher level than 5, they have experimental evidence for an aspect of QCD, which deals with the internal structure of protons and neutrons, which had previously been untested. Their results also show that the charm quark has some mass.