mesons

The discussion is if this is a real particle or are only two D mesons traveling together.

The list is pretty good, but mesons are an entire class of particle, not a particle, so although the new particle discovered is a meson it is not the meson.

There is no human-perceivable time interval over which cleaning up mesons could be meaningful.

The posible colors combinations of the mesons are red+antired, blue+antiblue and green+antigreen.

I thought the new particles were cool because they don't follow the color charge analogy, whereas mesons do follow the analogy?

Unlike normal mesons, which are a quark and its anti-quark, this is likely composed of more than just a pair of quarks; four or more.

It was the representation in SU of mesons for photon-photon collisions.

Impact on Understanding: • Mesons are now known to be the carriers of the strong force, which is one of the four fundamental forces of nature.

After that, everything is fixed, so that the SM makes definite predictions about where to look to find new baryons and mesons (things made out of quarks).

It's called CP violation, and we observe it in things like heavy mesons.

These quarks are bound together by the strong nuclear force, mediated by particles called gluons, and must combine in specific ways to form observable particles (mesons or baryons).

His work, however, laid the groundwork for the later discovery of mesons by Enrico Fermi and Richard Feynman, which was a major breakthrough in the field of particle physics.

Typically mesons (and other hadrons) create a "shower" of particles and by adding upp all their energies you can estimate what particle they came from.

This is not "mysterious"--CP violation is expected according to the Standard Model, it just hasn't been observed in baryons before, only in mesons, as the actual Nature paper [1] makes clear.

(Inside the particles, they interchange the color "constantly", so the exact colors don't mater.) (There are some technical details, that involve the symmetry properties, but this is the main idea.) The problem is that this system can split in two subsystems with total color "0" (for example, a pion and a J/psi mesons, or two D mesons.