Talk:Lepton

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Charge

The article states that "All known leptons have a negative or neutral charge." That statement is meaningless, as there is no fundamental reason one is a particle and the other is an antiparticle; by convention for leptons the particle is the negative one

--anon

The article no longer states this. Careful though: leptons can have positive, negative or neutral charge.

RobPlatt 11:07, 25 Oct 2004 (UTC)

IN cosmicastronomy.com IT IS WRITTEN THAT LEPTONS ARE RESPONSIBLE FOR VIRTUAL STEREO

Tau/Tauon?

Why is the Tau particle being called a Tauon throughout Wikipedia?

It's not, any more. --DannyWilde 01:57, 29 November 2005 (UTC)[reply]

Lepton numbers

This page lacks any info on lepton numbers. I'm not sure I'm qualified to add it without making mistakes :) But here's a summary:

-There are three lepton numbers: electron, muon, and tau. You can see a sumary here: http://hyperphysics.phy-astr.gsu.edu/hbase/particles/lepton.html#c7 That info should be probably be included in the articles table.

-Lepton numbers are conserved during decays. Apparantly this is only approximately true and there are circumstance where the conservation breaks, but I don't know much about that. :)

Good idea. Added a sentence. -- ALoan (Talk) 10:39, 10 Feb 2005 (UTC)

Lepton/Lepta?

Perhaps the plural form of Lepton should be written as Lepta (from the Greek Λεπτά).

This is never used in the particle physics communityJameskeates 12:32, 17 August 2006 (UTC)[reply]

Etymology

On the origin of the term "lepton" (from the OED, citing L. Rosenfeld Nucl. Forces p. xvii):

Following a suggestion of Prof. C. Møller, I adopt — as a pendant to "nucleon" — the denomination "lepton" (from λεπτόσ, small, thin, delicate) to denote a particle of small mass.

The Weak Doublet

There is something I don't understand in this article: what keeps the electron and the electron neutrino together? and the same question for the muon and tau and their neutrinos. - Henry Likos 22.42 09 August 2006

This is related to lepton number conservation mentioned above in the talk page. An electron and its neutrino have the same lepton number and this is conserved in all known interactions and the same for the muon and tau. A muon decaying to an electron for example must give off a muon neutrino so the muon number remains constant (as well as an electron anti-neutrino to balance the electron produced).Jameskeates 12:35, 17 August 2006 (UTC)[reply]

Neutrino Helicity

The article states that "only one helicity is observed for the neutrinos (all the neutrinos are left-handed, and all the antineutrinos are right-handed)." However, the article about neutrinos says that this is not true, since neutrinos do have a small mass, even if all neutrinos actually observed were left-handed. Maybe saying that "ALL the neutrinos ARE left-handed" is too strong a statement. Also, I believe that the sentence "The charged leptons have two possible SPIN states, while only one HELICITY is observed for the neutrinos" is confusing since it opposes two different concepts (spin and helicity) as if it were the same thing. I don't dare to fix all that (I'm still a physics undergrad, and not even a particle-oriented one), but maybe some of you could do it. - Arnoques 16.46 20 May 2007

bigger lepton

Feynman mentions observations of a larger lepton, c. 40,000 MeV he says, in a subscript to one of his books. Has this panned out? —Preceding unsigned comment added by 66.44.102.150 (talk) 03:52, 10 September 2007 (UTC)[reply]

no, it hasn't - in fact, there is experimental evidence from CERN in switzerland that the 3 known families of lepton (e,µ,tau) are all there is http://keyhole.web.cern.ch/keyhole/projects/number_of_families.html

cheers, -K —Preceding unsigned comment added by 139.18.249.104 (talk) 17:55, 30 January 2009 (UTC)[reply]

Table of leptons unclear

Below the table of leptons is some explanatory text that doesn't seem to make sense to me: "However there have been measured (indirectly based on the oscillation periods) the differences of the mass squares between the neutrinos, which have been estimated ..." - could somebody who knows what this is supposed to mean reword it?

Generally speaking: the neutrino of one falvour oscillates into other flavours. The parameters of these oscillations depends on value of (m1^2 - m2^2). The parameters of oscillations are known - that's why values of these differences are also known.

How about I change that line into "However, indirect measurements of the mass differences between the neutrinos have been made based on their oscillation periods. These oscillation periods are directly dependent on the differences of their mass squares."? SkyLined (talk) 17:23, 29 February 2008 (UTC)[reply]

It may be changed according to your suggestion.

May I suggest that you sign your messages so I know who is giving me the OK to make this change? You could be my kid-sister for all I know... SkyLined (talk) 12:22, 4 March 2008 (UTC)[reply]

Ethymology

Just above the ethymology, I found this: "The names "mu" and "tau" seem to have been selected due to their places in the Greek alphabet; mu is seven letters after epsilon (electron), whereas tau is seven letters after mu." - should that not be in the ethymogoly section? Also, this seems like an inverified assumption by an unknown person and there's no reference or source. Does anybody know what the real story is? SkyLined (talk) 20:42, 16 February 2008 (UTC)[reply]

Anomalous Magnetic Moment

Why doesn't the table of propreties of leptons include their anomalous magnetic moment? If nobody objects, I'm going to include it. Dauto (talk) 05:52, 24 February 2009 (UTC)[reply]

Sure go ahead. I suppose these anomalous ratios aren't known for quarks? Also could you review the mass of the neutrinos in the table. I'm not too sure about them.Headbomb {^ταλκ_{κοντριβς} – WP Physics} 10:52, 24 February 2009 (UTC)[reply]

Fixed lepton isodoublets figure

The lepton isodoublets figure had the leptons with the wrong isospin assignments -- every convention I've ever seen has the electric charge of the upper member of the isodoublet one unit larger than that of the lower member (in accordance with Q = T3 + Y). Apologies to Headbomb for replacing your figure. HEL (talk) 03:43, 1 April 2010 (UTC)[reply]