Talk:Quark

Up to down quark charge value change considerations

For an up quark with a +2/3 charge to change top a down quark with a -1/3 charge there has to be a change of minus 1 unit of charge. However there is no 1 unit of charge change value permitted for the properties of the 6 speculated quark entities. The change of the charge of the top quark to the top antiquark is from +2/3 to -2/3 or - 4/3 units of charge and the change of the charge of the bottom quark to the bottom antiquark is from -1/3 to +1/3 or a change of = 2/3 units. So it is not understandable as to how a unit change of a proton to a neutron can be accomplished by this theory.WFPM (talk) 19:44, 2 November 2013 (UTC)

That's because top quarks don't decay into top antiquarks (and vice-versa). If you want to change a proton (uud) to a neutron (udd), you change one up (+2/3) to one down quark (-1/3) by the emission of a W⁺ boson. See beta decay for more. Headbomb {talk / contribs / physics / books} 19:50, 2 November 2013 (UTC)

Thank you! So we must be playing with accumulated charge values around here and the W+ must be some kind of magic wand that subtracts a 1+ charge from an u quark and makes it a d quark, and the next question that comes is why it didn't have a +1 charge in the first place.WFPM (talk) 19:15, 3 November 2013 (UTC)

The "magic wand" is simply the conservation of electrical charge, although I'm not quite sure what you mean by "accumulated charge" and "why it didn't have a +1 charge in the first place". Headbomb {talk / contribs / physics / books} 02:40, 4 November 2013 (UTC)

Well if the +2/3 charge of the U can be converted into the -1/3 of the d by the emission of a +1, then we must be dealing with 3 separate entities whose individual charges can be "accumulated" and integrated into a "net sum". And of course the individual charges on the proton (and neutron} must be considered as being a "net sum" of the individual quark charges. So now the amount of charge of a particle has become a variable increment of some smaller than unit value. like maybe +-1/3?. So much for Gell Mann"s algebraic calculations.WFPM (talk) 20:42, 5 November 2013 (UTC However, if there is a possibility of the division of the electron (or the positron) into a number of smaller unit charge values, one would think that some evidence of such an occurrence would have cropped up in experiments related to the determination of the e/m value of these particles such as is carried in the Milliken oil drop e/m determination experiments.WFPM (talk) 04:04, 7 November 2013 (UTC)

Status of Higgs Boson

In relation to the recent reversion of my edit, in what way is the status of the Higgs boson still "under debate"? CERN scientists say that the particle discovered is a Higgs boson, they just don't know yet what kind of Higgs boson it is. A look at the Higgs boson Wikipedia page gives this: "The Higgs boson or Higgs particle is an elementary particle initially theorised in 1964, whose discovery was announced at CERN on 4 July 2012." So, we have the situation that people reading Wikipedia will be confused, there is conflicting information, is it or not a currently existing particle? CERN have announced its discovery. CMS spokesman Joe Incandela announced (http://home.web.cern.ch/about/updates/2013/03/new-results-indicate-new-particle-higgs-boson ) “The preliminary results with the full 2012 data set are magnificent and to me it is clear that we are dealing with a Higgs boson though we still have a long way to go to know what kind of Higgs boson it is,”. The scientific community has accepted that the new particle is indeed a Higgs boson. Whether it is the Standard Model Higgs boson or not is a different question, but it has been accepted as an existing particle.

Magnetic moment

What data are available about magnetic moment of quarks?--193.231.19.53 (talk) 17:10, 5 December 2013 (UTC)

In general, try the WP:REFDESK for questions like these. Or google. Headbomb {talk / contribs / physics / books} 17:16, 5 December 2013 (UTC)

I thought that someone working in particle physics, such as user Headbomb if I understand right, would know what data are available concerning this topic.--193.231.19.53 (talk) 11:08, 10 December 2013 (UTC)

It seems that there is a lack of determined data regarding the magnetic moment of quarks, as pointed out by googling [1].--193.231.19.53 (talk) 11:14, 10 December 2013 (UTC)

Best ordering for list of flavors?

From the article:
"There are six types of quarks, known as flavors: up, down, strange, charm, bottom, and top."
Wouldn't it be more orderly to list them as up, down, charm, strange, top, bottom (i.e. alternating up-type with down-type)? Naramatac (talk) 23:22, 25 December 2013 (UTC)

Are quarks observable or not?

Greetings, physicists! I am wondering about the seeming contradiction between two claims in the lead paragraph of this article. First we have "quarks are never directly observed or found in isolation" and then, later on, "All six flavors of quark have since been observed in accelerator experiments". This confuses me, and I wonder if there's some way it could be clarified or if maybe I'm just missing something? Thanks for your attention.— alf laylah wa laylah (talk) 04:12, 30 January 2014 (UTC)

Perhaps if we change the second one into "All six flavors of quark have since been indirectly observed in accelerator experiments"? - DVdm (talk) 08:33, 30 January 2014 (UTC)

Why was you confused? Leptons and photons can be isolated, but quarks and gluons cannot due to color confinement – it’s the main difference between those elementary particle that do not experience the strong force and those that do. But you also can’t isolate electron pair from an atomic matter, does it make the pair unobservable? Or does it make the pole of a magnet unobservable? Incnis Mrsi (talk) 09:35, 30 January 2014 (UTC)

No, look, I understand that elementary particles can be said to have been "observed" when predictions made from the assumption of their existence has been observed. That's what you're talking about here, right? Like what Thomson did with electrons. My only question is that for someone who doesn't know much about science it's very jarring to read that they can't be observed in isolation and then a few sentences later that they've all been observed. I'm not suggesting a change nor criticizing the article, which is excellent. I'm just pointing out something that confused me in case someone here wanted to know and possibly do something about it. I don't even know enough to assert that something should be done, but I do know that it can be hard for people immersed in technical subjects to see how their work reads to others. @DVdm, so that's what the second sentence means? Indirect observation? That's what I figured, but it's so hard to be sure.— alf laylah wa laylah (talk) 14:50, 30 January 2014 (UTC)

Indirect observation of quarks by direct observation of decay products, predicted by (or compatible with) the theory. We could even add a source like this

Wouldn't do much harm I guess. DVdm (talk) 15:50, 30 January 2014 (UTC)

It would have helped me. After some thought I figured out that you all must be using "observed" in that sense, but I'm fairly familiar with science, though not physics, and it still jarred me. I think someone who doesn't understand all the ways the word "observed" is used in science might have been more confused. Anyway, thanks for listening, and like I said, I don't know enough about it to suggest an edit.— alf laylah wa laylah (talk) 16:01, 30 January 2014 (UTC)

I have reworded that second sentence to "Accelerator experiments have provided evidence for all six flavors. The top quark was the last to be discovered at Fermilab in 1995."

It was a very good question and suggestion. Thanks for spotting it! - DVdm (talk) 18:33, 30 January 2014 (UTC)

Change infobox to mention flavors

Hey the infobox show the line: Types 6 (up, down, strange, charm, bottom, and top) Could it be changed to Flavors with a link to the article?186.231.123.122 (talk) 23:14, 9 April 2014 (UTC)

Quark mass diagram has a shading problem

A problem in https://en.wikipedia.org/wiki/File:Quark_masses_as_balls.svg :

The up quark is shown as a light, unshaded disk, which (wrongly) makes it look larger (more massive) than the down quark. Shading the up quark to match the others would fix this problem. Lightening the shading of the top quark would help, too — its wide, nearly-black border makes it a poor background for the other quarks, which themselves have nearly-black borders.