Talk:Muonium

Muonium
How can Muonium ( μ+e–) be "used to produce muon-catalyzed fusion in which muons shield the positive charge of the nuclei" when the charge of the Muon is positive? Are there details not told in the article or is it plain nonsense? 84.160.214.211 18:06, 28 August 2005 (UTC)


 * I believe it is incorrect. Muon catalysed fusion is done with &mu;- not &mu;+. This group studies fusion catalysed by "muonic molecules" consisting of a proton and a negative muon, the person who posted it was probably getting confused with that process. I've removed it from the article. -- Tim Starling 00:02, August 29, 2005 (UTC)
 * Sorry to chime in so late, but I agree. Muon-catalysed fusion is done with &mu;&minus;. -- Fcy (talk) 09:21, 22 November 2010 (UTC)

Any non-elastic interaction μ+e– goes into the associated neutrinos (anti-mu neutrinos and e neutrinos) and not in two photons as in e+e- or μ+μ– annihilation. I agree with Tim Starling. serbanut —Preceding signed but undated comment was added at 08:00, 15 September 2007 (UTC)


 * Yes, but let's not forget about the search for physics beyond the standard model. See, for instance, searches for mu -> e gamma, or for &mu;+e&minus; -> &mu;&minus;e+ (spontaneous conversion of muonium to anti-muonium, a search I'm personally familiar with (we didn't find it, but we only looked so hard, back in the 1980s)).  -- Fcy (talk) 09:21, 22 November 2010 (UTC)

What happens if you fuse two Muonium atoms with an oxygen atom? Does it make something simular to water? Mu2O Mayby?--24.121.0.194 (talk) 22:29, 8 October 2008 (UTC)


 * Why not? It would be awfully short-lived, though (&tau;&mu; ~2.2 microsecond). -- Fcy (talk) 09:21, 22 November 2010 (UTC)

What about atoms with electrons substituted by muons? What are their name/lifetime/properties? --Anton (talk) 18:12, 11 May 2009 (UTC)


 * Don't know what they're called, but they can't last much longer than a muon's lifetime (~2.2 microsecond). Since the muon has a mass about 200 times greater than that of an electron, their orbitals are commensurately smaller (hence the possibility of muon-catalyzed fusion).  I don't know for sure which electrons they'd displace, but I'd expect them to fall into 1s orbitals first, followed by 2s, 2p, . . . -- same as electrons, just closer in.  Perhaps they could be used to study nuclear structure?  But I'm just speculating; I don't know if anyone's used them for that purpose.  -- Fcy (talk) 09:21, 22 November 2010 (UTC)

Particle?
I removed the word "particle" from the definition of muonium, even though it appears in the IUPAC Gold Book cited. I studied physics, not chemistry, so I don't know whether or not this is normal usage in the context of chemistry but, in the context of physics, muonium is an atom, not a particle. --Fcy (talk) 01:01, 23 June 2010 (UTC)

Nomenclature
Hey, can somebody chime in regarding the nomenclature? I know that most of that paragraph is correct, but I kind of doubt the passage about muium. After all, the particle is called muon, not mu (even though that is the letter that usually represents it, of course). Is it common to only use a part of the original positive particle's name as basis to then add -ium? Otherwise "true muonium" should have been called muononium, and the passage about irregular nomenclature should be changed accordingly. Please note that I do not intend to rename particles, this is just about the explanation in the text. :) --RealZeratul (talk) 15:31, 21 November 2016 (UTC)


 * I hope that discussions of nomenclature are just a tempest in a teapot. IUPAC says "muonium".  The Particle Data Group says "muonium". Citation: P.A. Zylaet al.(Particle Data Group), Prog. Theor. Exp. Phys.2020, 083C01 (2020), https://pdg.lbl.gov/2020/listings/rpp2020-list-muon.pdf


 * Maybe the problem originates with positronium? Is that the bound state of a positron and an electron, a hydrogen-atom analogue, or is it the bound state of a positron with its antiparticle, which latter just happens to be an electron?  I suppose it could depend on the context.


 * One could look at other hydrogen analogues, such as deuterium, a bound state between a deuteron and an electron. We don't call it "deuteronium".


 * The Particle Data Group also has a recently revised section on Hadron Naming, https://pdg.lbl.gov/2020/reviews/rpp2020-rev-naming-scheme-hadrons.pdf, in which they do not use names like charmonium except in a generic sense. Any particular bound state has its own, unique, name, based on the most massive of the quarks, see Section 8.3.


 * I think user RealZeratul makes a strong case for calling "muononium" rather than "true muonium", if "-onium" is supposed to mean particle and antiparticle, as opposed to "-ium" for atoms.  But then, this is all just a matter of history, now, and at Wikipedia we just report on what others say, we don't advance our own research.


 * Fcy (talk) 23:20, 8 June 2021 (UTC)