The tau particle (so named because it was the third charged lepton, behind the electron and muon) was discovered in the 1970s by Martin Perl and colleagues. In one of the SLAC papers, Perl refers to the particle as the "$\tau$ lepton".

I've heard the particle referred to as the "tau", the "tau lepton", the "tau particle", and other variants substituting in "$\tau$" for "tau". I've also heard it referred to as the "tauon", in keeping with the muon and electron. I've only heard it used from a few sources, though. I have no idea where the term originally came from, though.

As an interesting side note, the Wikipedia talk page is in a furor over this. I have no idea if anyone on that page is actually who they say they are, or if any sources they give are true, but it seems that regardless of whether or not "tauon" is a valid term, nobody seems to know where it comes from.1

Where did the term "tauon" come from? Was it from Perl, or was it from someone completely different?

1 In theory, there have been worse disputes, but I find the "tau"/"tauon" one more amusing.

  • $\begingroup$ I see, so the cartoon is reality-based... $\endgroup$
    – hjhjhj57
    Apr 12, 2015 at 0:42

1 Answer 1


This Wikipedia thread is hilarious, but it is not hard to figure out where "tauon" came from after muon, pion, kaon, etc. When the same type of abbreviation is used enough times people start treating it as a generating rule, it's the same with other types of linguistic formation. It's a wonder we don't have rhoons, omegaons as well, maybe they just don't sound as good.

Tauon is a natural abbreviation of "tau-lepton", so it wouldn't surprise me if the original editor of the Wikipedia page and/or the astronomers mentioned in the thread came up with it on their own. It wouldn't surprise me either if eventually it becomes accepted usage. The reason for pushback may be that initially such abbreviations were applied to mesons, starting with "mu-meson", originally mistaken for a meson, and shortened to "muon", when it became clear. In fact, muon is a mu-lepton, although it is not usually called that, but it is only natural to want uniform naming for both mu and tau leptons. People who know that muon was originally mu-meson are unlikely to infer from the name that "tauon" is a meson, if that's the concern.

This thread reminded me of Origins of Mathematical Words by Anthony Lo Bello, where he rages against word formation in mathematics. For example, "repunit" is "a ludicrous word, a comical abbreviation of repeated unit... One should not do this sort of thing unless one's purpose is to be ridiculous". "Nonhomogeneous" is terrible because "non" is Latin, and "homogeneous" is Greek, and "isometry" is because although both parts are Greek, they are not spliced together as in Greek. I am not sure if Lo Bello realizes how comical his own objections are. But fortunately in the end common usage always wins over lexicographers.

  • $\begingroup$ At least in spanish, "nonhomogeneous" sounds awful, inhomogeneous being the natural option, and thinking a little bit more about it, I think the right word would be heterogeneous. I'm curious as to what the right word for "isometry" should be. $\endgroup$
    – hjhjhj57
    Apr 12, 2015 at 21:38
  • 2
    $\begingroup$ @Javier "Inhomogeneous" is just as terrible since "in" is also Latin, the 'correct' word according to Lo Bello is "anhomogenic". Isometry is "the English form of the make believe Greek word $\iota\sigma o\mu\varepsilon\tau\rho\iota\alpha$", he doesn't say what the 'correct' word might be. Guess what he thinks about "homosexual", "neuroscience" and "television", such mixtures are called macaronic. $\endgroup$
    – Conifold
    Apr 12, 2015 at 23:50

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