Talk:Top quark

message: Hi everybody, just wanted to point out that the figure is wrong: the W boson cannot decay to a bottom and a charm. I am sure someone here has the original figure and can fix that?  — Preceding unsigned comment added by 5.172.125.72 (talk) 17:22, 15 September 2015 (UTC)
thread_title:  Wrong plot 

message: top lifetime is wrong!  — Preceding unsigned comment added by 105.135.86.193 (talk) 18:21, 25 February 2014 (UTC)
replies: text:  Now it is :P, as are all all fundamental particles (or will all soon be).  See Wikipedia:WikiProject Physics/Projects of the Week for reasons.Headbomb (ταλκ · κοντριβς) 22:41, 14 June 2008 (UTC)

text: I can't figure the logic by which you decided strange quarks are of Mid importance, but tops are of High importance. Surely the lighter strange quark is more relevant to real-world physics. Think strange quark stars or strangelets. The top is only relevant to beyond-the-Standard Model probing. -- Xerxes 17:16, 6 June 2006 (UTC)
replies: text: I'm not sure what you mean by "real-world physics"? The top quark is a topic of active ongoing research. There isn't much new being studied or discovered when it comes to the lighter quarks (except maybe bottom). Bodhitha 15:11, 22 June 2006 (UTC)

text: The top quark is relatively new news and an active area of research.  The strange quark, as far as I'm aware, is not.  Quark stars and strangelets are entirely hypothetical, and I really don't know what you mean by "real-world" physics. It really doesn't have any properties more interesting than the up and down, and all the strange particles were discovered before quark theory.  I wouldn't have rated the strange quark at all except that I was testing the rating system. -- SCZenz 19:18, 22 June 2006 (UTC)
replies: text: Well put. The road of assigning importance to purely hypotheticals (quark stars, etc.)  is a slippery slope.  Bodhitha 19:47, 22 June 2006 (UTC)

text: I see no reason why active research should have any bearing on importance. There's no cutting edge research on atoms, anatomy or arithmetic, but these are crucial foundations of science. Encyclopedic importance should be inversely proportional to a subject's distance to the cutting edge. -- Xerxes 23:52, 22 June 2006 (UTC)
replies: text: Maybe the key here is importance "within physics" as it states, not necessarily encyclopedic importance? Bodhitha 03:58, 23 June 2006 (UTC)

text: Xerxes, I don't think that's true even for print encyclopedias; they tend to have large, detailed articles on current issues which shrink over time as the editors put the subject into historical perspective.  The fact of the matter is, for the next several decades at least, I anticipate that people are far more likely to look up the top quark than the strange quark.  Thus on the much-shorter timescale on which Wikipedia changes, having this article up to standard is the most important—which is ultimately what these importance ratings are for. -- SCZenz 06:07, 23 June 2006 (UTC)

text: Also, don't forget that most of the interesting facts about the strange quarks are actually interesting facts about the kaon (probably High importance) or other particles, or about its relationship to the Eightfold way (High importance) or the quark model (Top importance).  The strange has its thunder stolen, in a real sense, by hadronizing; there's not much left to say about the quark itself after all that.  Some day the interesting facts about the top quark may perhaps be in the Supersymmetry article, once we understand that the top Yukawa coupling equals one exactly and it was telling us what new physics to look for the whole time, but that day has not yet arrived; the interesting info on the top quark all goes in this article in the meantime.  -- SCZenz 06:17, 23 June 2006 (UTC)
replies: text: Well, perhaps we should think of it this way: which of the elements of the periodic table would you omit if you had to choose one? or which of the five kingdoms of life? There are only six quarks. By what criterion could you choose one over the others? Maybe it's not really that important; I'm sure all six quark flavors will make it into whatever canonical edition is being cooked up. -- Xerxes 19:27, 23 June 2006 (UTC)

text: There are some very fundamental things that set aside the top quark from all 5 others. Among them are the fact that it is the only quark that you can study in "bare" form (since it decays before it ever hadronizes). It is also the *only* (known) fermion with a mass anywhere near the EWSB scale and as thus may offer unique insight into that mechanism. Bodhitha 22:24, 23 June 2006 (UTC)
thread_title:  Importance discussion 

message: Press release from Rolf Heurer: 
"Chicago, USA and Geneva, Switzerland, 19 March 2014. Scientists working on the world’s leading particle collider experiments have joined forces, combined their data and produced the first joint result from Fermilab’s Tevatron and CERN’s Large Hadron Collider (LHC), past and current holders of the record for most powerful particle collider on Earth. Scientists from the four experiments involved—ATLAS, CDF, CMS and DZero—announced their joint findings on the mass of the top quark today at the Rencontres de Moriond international physics conference in Italy.
 
Together the four experiments pooled their data analysis power to arrive at a new world’s best value for the mass of the top quark of 173.34 ± 0.76 GeV/c2."
That breaks down as 173.34±0.27(stat)±0.71(syst) GeV (http://arxiv.org/abs/1403.4427).
Graphics are available at http://www.interactions.org/cms/?pid=2100&image_no=OT0172.
Pulu (talk) 20:54, 19 March 2014 (UTC)
thread_title:  Updated Top Mass Result 

message: I have a rule of thumb about particle physics equations.  If I can't make heads or tails out of it, despite being a grad student (albeit an experimentalist), it may be too complex for a general-use encyclopedia.  And I have to say I don't understand the the Electroweak symmetry breaking section; in particular, I don't understand the purpose.  Is the idea that the proximity of the top mass to a fixed point in the SM RGE is an argument for the MSSM or other supersymmetry model?  If so, that should be made explicit, just for starters. One could also ask if we need all those equations, and if the top quark article is really the right place for that argument. -- SCZenz 02:13, 27 January 2006 (UTC)
replies: text: I kinda like it, tho it certainly could use some clarification. There are also some fascinating things that have been postulated in so-called topcolor models, which use technicolor but have top quarks as techniquarks. -- Xerxes 04:31, 27 January 2006 (UTC)
replies: text: A general discussion of the implications of the top quark mass for various physics models would be very appropriate here.  But this is a lot of detail about one issue, and rather vague to boot. -- SCZenz 06:38, 27 January 2006 (UTC)
thread_title:  Electroweak symmetry breaking section 

message: I'm uncomfortable with the wording.  The article states "It was discovered in 1995 by the CDF and D0 experiments at Fermilab". Surely this should read "It was first observed...". Theorists predicted it before then, and as such it was expected to turn up at some high mass.
Apologies if I've missed a previous discussion on use of the word "discovered". I've had a look around and couldn't see anything conclusive.
86.15.240.245 04:26, 28 November 2006 (UTC)
thread_title:  A small problem with the wording 

message: The top quark needs to stay with two other quarks or an antiquark. The strong force overrides the other three forces.--67.10.200.101 06:18, 30 June 2007 (UTC)
replies: text: No, the top quark really does decays well before it has time to find the quarks that would make it color neutral.  The decay width of the top quark is 1.5 GeV while the hadronization time scale is 1/0.2 GeV.  See for instance "Jets from massive unstable particles: Top-mass determination"  by Fleming, Hoang, Mantry, and Stewart  (hep-ph/0703207) that exploits this property to argue that the theoretical uncertainty on the top quark mass is much less than that of other quarks -- the order of uncertainty is    \Lambda_{\text{QCD}}^2/\Gamma_{\text{top}}.  jay 07:04, 30 June 2007 (UTC)
thread_title:  The top quark DOES hadronize 

message: Someday I want an R baryon to appear, with three top quarks, a spin of 3/2, and a charge of +2. I know that it's not normally possible, but I do wish for a longer lifetime for the top quark.--Mathexpressions 03:44, 11 July 2007 (UTC)
thread_title:  R Baryon 

message: the t-Quark does have 172.5 ± 2.7 GeV by partical group ->http://pdg.lbl.gov/2007/listings/q007.pdf  —Preceding unsigned comment added by 87.123.231.207 (talk) 04:43, 20 February 2008 (UTC)
replies: text: Note that in the first paragraph of the paper you provide, it states, "Including the most recent unpublished top mass measurements from Run-II, the TEVEWWG reports an average top mass of 170.9 ± 1.1 ± 1.5 GeV".  This newer figure has since been published, and is given correctly in this article. -David Schaich Talk/Cont 06:00, 20 February 2008 (UTC)
thread_title:  actuality 

message: Decay branching ratios were just added to the infobox.  Can this information be put in the article itself, along with the source?  I don't see it in the PDG, but perhaps I'm just not looking in the right place. -David Schaich Talk/Cont 16:57, 27 July 2009 (UTC)
replies: text: They were in the main text before (also without source), but where removed in my revision/expansion of the decay section. They are simply the magnitudes squared of the relevant CKM matrix elements (due to the high mass of the top, the masses of the decay products can be safely ignored.) The only branching ratio that has been measured is the t->b decay, which is in the text. The decay section should probably be expanded by a sentence or two about the theoretical values of the branching ratio. (with an appropriate source). (TimothyRias (talk) 09:18, 28 July 2009 (UTC)
thread_title: Decay branching ratios

message: See Talk:Quark#Harari's quark model. Headbomb {ταλκκοντριβς – WP Physics} 00:05, 22 February 2010 (UTC)
thread_title:  Harari's quark model 

message: 2010 PDG values have been posted, http://pdg.lbl.gov/2010/2010/tables/rpp2010-sum-quarks.pdf
I will wait a few more days before making the changes to mass. If there are no objections I'll apply the changes on Friday August 06, 2010 sometime between 0700 and 2200 UTC.
Abyssoft (talk) 20:31, 2 August 2010 (UTC)
thread_title:  New reference 

message: Added link to full text on arxiv. Someone may wish to remove the reference to the article as published in Prosper's book. It's better to refer to the version everyone can freely access electronically. --Biggus Dictus (talk) 18:03, 13 October 2011 (UTC)
thread_title:  Willenbrock reference 

message: There a several passages in the article that are speculative over the existence or mass of the Higgs boson, particularly 'using the bare quark and extensions of the standard model to predict the Higgs Boson's mass'.
The Higgs boson was first confirmed in 2013 with a mass between 125 and 127 GeV/(c^2). 
Should the article be rewritten to reflect this?  — Preceding unsigned comment added by 2001:630:E4:4220:F0A7:549B:32AC:5019 (talk) 01:48, 5 February 2017 (UTC)
replies: text: removed redundant version of the above and the response is, except in as much as the Higgs field is supposed to be source of all mass, no, it's irrelevant to this article. I still don't get as I've noted on the back matter to gluon how people in these articles talk about observing things that have been stated from the jump to be non-observable. What you have is that experiments are done, and particles that ARE observable are observed in conditions that are consistent with the theory asserting the existence of the unobservable particles, then some people are then merrily skipping forward to say that the unobservable has been observed. I heard a physicist (Kraus) the other day deride philosophers for saying that they were clarifying when they were obfuscating. I also just saw Sean Carrol make clear the equivocation on "mass" in a video, showing that at least some physicists are capable of careful and precise use of language. When I heard that the mass of the truth parton was comparable to that of a gold atom, I came here to see if the observation thing was perseverated, and bingo. 98.4.124.117 (talk) 01:27, 4 July 2018 (UTC)
thread_title:  Updating since Higgs Boson discovery and mass confimation 

message: An editor has asked for a discussion to address the redirect Heaviest subatomic particle. Please participate in the redirect discussion if you wish to do so.  Steel1943 (talk) 20:39, 20 September 2019 (UTC)
thread_title:  "Heaviest subatomic particle" listed at [[Wikipedia:Redirects for discussion|Redirects for discussion]] 

message: Hi all, these two paragraphs under the section about Higgs coupling have some redundancy:
"The Standard Model generates fermion masses through their couplings to the Higgs boson. This Higgs boson acts as a field filling space. Fermions interact with this field in proportion to their individual coupling constants y i {\displaystyle y_{i}} y_{i}, which generates mass. A low-mass particle, such as the electron has a minuscule coupling y electron = 2 × 10 − 6 {\displaystyle y_{\text{electron}}=2\times 10^{-6}} {\displaystyle y_{\text{electron}}=2\times 10^{-6}}, while the top quark has the largest coupling to the Higgs, y t ≃ 1 {\displaystyle y_{\text{t}}\simeq 1} {\displaystyle y_{\text{t}}\simeq 1}. These couplings are usually called the Higgs–Yukawa couplings, and they vary slowly as the energy scale at which they are measured is varied, due to a quantum effect called the renormalization group.
In the Standard Model, all of the quark and lepton Higgs–Yukawa couplings are small compared to the top-quark Yukawa coupling. This hierarchy in the fermion masses remains a profound and open problem in theoretical physics. Higgs–Yukawa couplings are not fixed constants of nature, as their values vary slowly as the energy scale (distance scale) at which they are measured. This dynamics of Higgs–Yukawa couplings, called "running coupling constants", is due to a quantum effect called the renormalization group."
150.135.165.22 (talk) 03:38, 21 November 2020 (UTC)
thread_title:  Redundant Paragraphs 

message: I'm not familiar in this subject, but was wondering if this was in wikipedia.
 - Observation of the associated production of a top quark and a Z boson in pp collisions at s√=13 TeV with the ATLAS detector.  Thanks, Marasama (talk) 22:23, 22 November 2020 (UTC)
thread_title:  Has the tZq quark been talked about? 

message: This is wrong.  There is no coupling to the Higgs Boson.  The coupling is to the Higgs Field. 134.171.73.35 (talk) 10:55, 31 October 2023 (UTC)
thread_title:  Mass and coupling to the Higgs boson