Talk:Quarkonium

The news release at [1] that announces Y(4260) also mentions some others that are not in this article: "DsJ (2317), the DsJ (2458), and the X(3872)"

Spelling standard: British or American

The first paragraph uses both 'flavorless' and 'flavourless'. Which should this article use? 12.149.13.1 14:50, 9 August 2005 (UTC)

I thought we had standardized on British, but people keep changing it. There is no one true spelling. Arxiv favors the American spelling by 3:1 but that's hardly an overwhelming ratio. -- Xerxes 19:36, 27 November 2005 (UTC)

And it just indicates there are more Americans submitting papers. This article, as all articles, should use whatever happened to be used first. -- SCZenz 19:41, 27 November 2005 (UTC)

If that were true, then we'd all be using archaic spellings. See you down at ye olde publick house. -- Xerxes 21:18, 27 November 2005 (UTC)

It's a wikipedia rule that whatever the initial author uses, should be kept throughout the article. -- Tijmen

Quarkonium vs. quark

I'm not a wizz on particle physics so i wont try and edit this page although there seems to be a disagreement here. This article states that a Quarkonium is a flavourless meson yet the wilkopedia entry for meson states that a meson is composed of fermions i.e. quarkonium and gluons. So which is it?/

You're confusing quarks with quarkonium. They're two different things. Quarkonium is a bound state of a quark and the corresponding antiquark. This is a special case of a meson, which is a bound state of a quark and any antiquark. -- SCZenz 19:41, 27 November 2005 (UTC)

Perhaps I am missing something here, but shouldn't this particle be called the quarkon? Likewise charmon (not charmonium), bottomon (not bottomonium) etc.? Nearly all other particles are named using the classical Greek neuter nominative singular suffix -on (e.g. proton). The Latin i-stem neuter nominative singular -ium seems to be reserved for chemical elements (like chromium) or phases of matter such as quarkium (QCD matter) or neutronium (degenerate matter). Apparently it's an established usage, but isn't physics all about systematization? --Ziusudra (talk) 21:23, 23 October 2008 (UTC)

See Onium. Headbomb {^ταλκ_{κοντριβς} – WP Physics} 05:33, 21 September 2009 (UTC)

The principle as far as I can see is that the Greek neuter is used for particles seen as fundamental, and the Latin for 'particles' viewed as compound systems. Charmonium is named as such because (what with all its excited states) it is treated analogously to an atom - very much a combination of charm and anticharm. If 'charmon' were to be used, it would be for the charm quark. 'Protons', 'neutrons', 'pions' and 'kaons' were named before the quark model, so they were seen as elementary at the time, and the name has stuck. The muon and electron, tauon, and a whole lot of pseudo-particles and hypothetical particles have kept their names. The neutrino was originally called a neutron when first hypothesised by Pauli, but the scientific community agreed to use that for what we use it for now, and the neutrinos were given the name 'neutrino' because they were much less massive, but still neutral - an apparently elementary lepton and a compound hadron may seem to have nothing to do with each other now, but only the electron, proton, neutron, neutrino and their antiparticles were known at the time, so it made sense then. That's the trouble with progress - you don't get a chance to choose the right convention in advnace - hence strangeness counting strange ANTI-quarks, Franklin's charge convention causing problems with engineers (electrons are more important in electricity in practice), and many other examples. Physicists only pretend care about simple, practical common sense - but they come up with conventions like measuring energy in cm^{-1}, just to confuse people.

This bit has me confused:

This usage is because the lighter quarks (up, down, and strange) are much less massive than the heavier quarks

So far, that's just tautology.

and so the physical states actually seen in experiments are quantum mechanical mixtures of the light quark states.

Why is this, and as opposed to what? David (talk) 22:07, 23 July 2010 (UTC)

Daggers

Note 2 and Note 3 both have a dagger, it is difficult to figure out which is which. I'm not good enough at wikipedia myself but someone should fix this. -- Tijmen

Quark-Antiquark annihilation?

It would be helpful if someone could explain why a quark-antiquark particle doesn't just annihilate itself. 146.115.34.7 (talk) 22:24, 23 March 2009 (UTC)

They do annihilate, in the sense that they are unstable particles with short lifetimes. —Preceding unsigned comment added by 118.92.173.15 (talk) 23:16, 2 January 2010 (UTC)

Term symbol

The "term symbols" are not the term symbols referred to on the term symbol page. The present page has a leading number (the n of n^{2S+1}L_J, the definition of term symbol does not have the leading n). What is the leading n? —Preceding unsigned comment added by 118.92.173.15 (talk) 23:12, 2 January 2010 (UTC)

bottomonium pun

bottomonium is how some college students call homosexuals. It's not that evil, because they would make a joke anyway. Jokes aren't immediately evil. Jokes exist for everything! Overprotection is unwise! Let them use a sci-joke, because they are able of pure filth! — Preceding unsigned comment added by 2A02:2149:8703:DF00:E845:F2D3:F903:2141 (talk) 00:20, 21 September 2017 (UTC)

New Particles

On 2013-03-26, the BESIII collaboration catches new particle announced the discovery of a new particle Z_c(3900). 152.178.49.145 (talk) 16:36, 16 April 2013 (UTC)

References