Quarks

[Dr Who]

I know there was an experiment done where high energy electrons where fired at protons. From the scattered pattern produced by the electrons, it was found that protons have a non-uniform distribution of mass and charge. This helped to confirm the existence of quarks because they would case the proton to have a non-uniform distribution of mass and charge. However, I was wondering what other experimental evidence is there that quarks exist?

 

Thanks in advance for your comments.

[timo]

Pretty much every particle accelerator experiment conducted since, I guess. Not sure about other experiments, but I could imagine something in the direction of quark-gluon plasma experiments and primordial nucleosynthesis.

[Dr Who]

Pretty much every particle accelerator experiment conducted since, I guess. Not sure about other experiments, but I could imagine something in the direction of quark-gluon plasma experiments and primordial nucleosynthesis.

 

Thanks for your comment Timo, I will have a look around in those areas. However, do you know of any particular experiments that I should look for?

[timo]

Nope. I'm not much into the history of experimental physics. Currently running experiments would be ATLAS/CMS and ALICE at the LHC. The former (ATLAS and CMS) try (amongst other things) to get a more precise measurement of the top-quark mass, the latter (ALICE) is concerned with creating quark-gluon plasma (that in its theoretical description presumably foots on the existence of quarks). Technically, both experiments would qualify as being different from "electrons were fired at protons", since it's proton-proton and lead-lead that is shot onto each other. But at least the proton-proton case is admittedly quite similar to electron-proton.

[Enthalpy]

A handful of quarks, combined according to simple rules, explains hundreds of particles, once you tell these are composed of quarks.

The interactions of composite particles follow "simple" conservation rules if described at the quark level.

Desriptions at the quark level have predicted composite particles that were later observed, including excited states of these compositions.

This is what one calls a successful model.