User talk:Cjean42

Hello world! Cjean42 (talk) 15:44, 10 July 2012 (UTC)[reply]

your images in the particle physics articles[edit]

Hey Cjean42, I noticed that you have been attaching what appear to be self-produced diagrams all over the particle physics articles.

Now, one problem with those diagrams is that they are very unclear (and I write this with a certain knowledge of the subject - check my contributions to convince yourself). Look e.g., at the diagram that you posted in the Higgs article: what is on the axes? what do the different colors and different symbols represent? All of those things may have a meaning for you, but they are meaningless to the reader. Another (perhaps bigger) problem is that your diagrams appear to reflect your personal interpretation of the concepts depicted, and they do not resemble very much any standard diagram in the scientific literature (please correct me if I'm wrong). In other words, those diagrams amount to original research, and as such they do not belong in a Wikipedia article (check the guidelines to convince yourself).

Unless you can show that your diagrams do in fact reflect the standard of the scientific literature, I will remove them from the particle physics articles. I hope you take this the right way, i.e. not as a personal attack against you but rather as an attempt to ensure the clarity of the articles and the respect of the guidelines of Wikipedia. Cheers, Ptrslv72 (talk) 12:12, 1 December 2012 (UTC)[reply]

Hello Ptrslv72. I am a bit surprised the content of these diagrams would be unfamiliar, but respect the issue you've raised. These are simply plots of the known standard weak hypercharge and weak isospin (and strong force) charges of the known elementary particles. Or, for their more mathematical origin, they are weight diagrams, familiar to particle physicists since at least the 30's, originally used for plots of electric charge and isospin. (There is a well known textbook reference by Georgi.) Perhaps my use of W for the weak isospin axis, which might be given the more standard label T₃, and Y for the weak hypercharge axis, which might be given the more standard label Y_W, is confusing? Cjean42 (talk) 20:07, 1 December 2012 (UTC)[reply]

Since I already know what weak hypercharge and weak isospin are, as well as the charges of quarks and leptons, I can figure out the meaning of all of the symbols in the diagram. However, the target reader of a Wikipedia article is not a physicist. What the average reader sees in the diagram are three axes without any values on them, and a bunch of arrowheads of different colors (blue, dark blue, grey and yellow), some pointing left, some pointing right, some with a square on top, plus two yellow circles and a white one. You tell the reader that those are "all known elementary particles", but which is which? And more importantly, what information do you want to convey? If it is just the hypercharge and isospin assignments of the SM particles, well, the diagram does a rather bad job at it. A simple table would be much easier to understand (and anyway I would question the need for such a table in the "Higgs boson" and "Higgs mechanism" articles). If on the other hand you see some deeper meaning in the "pattern", you should as well explain what this meaning is, and why it is relevant to the article, and you should prove (by quoting in the article a suitable source) that you are not just pushing a personal interpretation of yours. In the current state of things, I suspect that all the readers can see in those diagrams are just fancy clusters of colored spots without much information content. Cheers, Ptrslv72 (talk) 23:05, 1 December 2012 (UTC)[reply]

Ah, I see. So do you think it would be better if the caption included the description: "The yellow glyphs are the eight different varieties (states) of the electron, including left and right chiralities, spin up and down, as well as anti-particles (positrons). The blue glyphs are up quark varieties, down quark purple, and neutrinos grey. The yellow circles are W+ and W- bosons, and Z_0 and photon white circles in the center. The four Higgs field states are shown as squares, including the electrically charged states in yellow and the neutral Higgs grey."? I think you agree that these states and their charges are completely standard. But I hope you will also agree that it's useful to have the pattern presented in a plot, rather than just in a table. The information conveyed is the hypercharge and weak charge structure of the Standard Model, how the Higgs field works in this context to determine the weak mixing angle, how hypercharge and weak charge combine to give electric charge, and how the neutral Higgs can provide particles with mass by interacting with their left and right chiralities. Once again, all of this is completely standard, is visible in this diagram, and would not be obvious in a table. Please see the isospin article for precedence. It was my hope that assembling this standard data and presenting it in these diagrams would be helpful to a reader. Cjean42 (talk) 01:01, 2 December 2012 (UTC)[reply]

A plot can be more useful than a table if it makes the information in the table more readily accessible to the reader (which is definitely not the case here) or if the "pattern" itself contains more information than the numbers in the table. In this respect, it may be true that your diagram depicts "how hypercharge and weak charge combine to give electric charge", although it would help if you added values on the axes and explained what the different symbols stand for. However, to say that it also shows "how the Higgs field works to determine the weak mixing angle" and "how the neutral Higgs can provide particles with mass by interacting with their left and right chiralities" seems quite a stretch to me. Again, this may seem clear to you, but it is definitely not clear to the reader, and I am afraid that making it clear would require tons of additional explanations which would ultimately defeat the purpose of the figure (as well as a link to a reliable source to show that your way of depicting the Higgs mechanism is standard in the literature).

Therefore, it seems to me that a plot like yours - with the improvements discussed above - could be of some use in the Weinberg angle and/or Electroweak interaction articles, but not so much in the Higgs boson and Higgs mechanism articles. The Standard Model (mathematical formulation) article already has tables with all the charge assignments and an explicit discussion of the weak mixing, thus it would not benefit much from an additional plot, whereas the Standard Model article might or might not benefit - depending on how readable the improved plot becomes. Cheers, Ptrslv72 (talk) 12:36, 2 December 2012 (UTC)[reply]

Thanks, these comments are constructive. Maybe how the neutral Higgs works in this diagram, to break EW symmetry, could be more clear. If you would, have a look at the diagram again. When it gets a vev, the neutral Higgs determines the weak mixing angle. In the diagram, the electric charge axis must be perpendicular to the vector out to the neutral Higgs, which has nonzero weak isospin and weak hypercharge. This determines the weak mixing angle. Also, these charges are conserved in interactions. When the neutral Higgs interacts with one fermion chirality, it produces the other chirality, which you can see in the diagram by vector addition. Plotting the particle charges out in this diagram makes all of this structure more accessible to the reader than it is in a table, even if it's the same standard information -- don't you agree? If you don't object, I'll work on better labeling and replace the figure. Cjean42 (talk) 18:22, 2 December 2012 (UTC)[reply]

Sorry, I have a hard time seeing any of this in your diagram (BTW, the weak mixing angle is determined by the values of the SU(2) and U(1) gauge couplings), and I seriously doubt that the average reader would find "this structure more accessible". Moreover, as I already mentioned a few times, this way of presenting the subject is quite non-standard: you must refer to some reliable source, otherwise it falls into original research. I propose that we paste this discussion in the talk page of the Higgs boson article and see what the other regular editors think about it. Cheers, Ptrslv72 (talk) 21:17, 2 December 2012 (UTC)[reply]

OK. The relative strengths of the SU(2) and U(1) couplings is shown via the relative scaling of the W and Y axes, determining the weak mixing angle fixed by the neutral Higgs. If I understand the guidelines on images correctly, plots created from standard known data are not OR. If you don't mind, give me some time to update the figure first, based on your previous comments, before we discuss it on Higgs boson talk page. Cjean42 (talk) 22:19, 2 December 2012 (UTC)[reply]

I pasted our discussion here for the other editors to see, and left a note on the talk page of two editors (FT2, TR) who have recently been active on the article. From now on, please post your comments on that talk page (I won't have much time to devote to this business in the coming days). Cheers, Ptrslv72 (talk) 22:15, 2 December 2012 (UTC)[reply]

Ah, my request was too late. OK, I'll go talk with what I've got. Cjean42 (talk) 22:19, 2 December 2012 (UTC)[reply]

Whoops! My bad, I didn't wait long enough for your reaction. Anyway, you can just write on the talk page that you need some time to update the figure, there should be no problem with that. As I said, I myself will be rather busy with other stuff until the end of the week. Cheers, Ptrslv72 (talk) 22:26, 2 December 2012 (UTC)[reply]

Hey Cjean42, I think your diagrams are useful, but I don't understand some parts of them. Specifically about http://en.wikipedia.org/wiki/File:Standard_Model.svg -

you had a right idea when you depicted each quark as a tight group of three colored arrows - this tells reader that there are three different particles in this location. Can you use the same technique to "uncram" other locations where you have more than one particle in the same place (such as H and right-anti-neutrino)? Currently, they are drwn one on top of the other.
same applies to the mess at (0,0). There are Z, gamma, and (looks like) gluons. Way too crowded -> not readable.
leptons and quarks are depicted with arrows. What directions of these arrows mean?
why there are six gluons, not eight?
what g, g8 and g3 labels near (0,0) try to explain?
what is H*?
looks like circles are reserved for spin-1 particles and squares are for spin-0 ones, but why some squares are turned 45 degrees? Does this mean anything?

209.132.186.34 (talk) 16:16, 9 January 2013 (UTC)[reply]

Hello 34, thanks for these questions.

To "uncram" the H and right-handed neutrino, we would have to spread them out according to their spin charge. Would you (or anyone) like to help me do that? We would have to plot the up and down spins, possibly along separate axes for left and right handed parts of the spin connection. Also, there's no conventional way to uncram the second and third generation fermions.
We could spread out the gluons, but then the colored quarks would also separate and we wouldn't see that clustering you like. The Z0, gamma, g3, and g8 all have zero charge, so they can't be uncrammed from the diagram origin. (Technically, they're the Cartan subalgebra generators for the diagram.)
The glyphs are different for each of the eight possible Dirac fermion states: pointing up or down for particles or anti-particles, left-handed or right-handed, spin up or spin down.
Two of the eight gluons, g3 and g8, have no color (or any other) charge.
The g is a general label for the gluons. I didn't want to crowd the origin further by labeling each gluon individually.
I'm following convention as closely as possible. The Higgs field is a complex doublet with phi+ and phi0 the two complex components. This results in four eigenstates: the neutral Higgs, H, its complex conjugate, H*, the charged Higgs, phi+, and the conjugate, phi-. Three of these four degrees of freedom get "eaten" by the W+,W-, and Z0.
The rotated squares signify the conjugate eigenstates.

Cjean42 (talk) 18:50, 14 January 2013 (UTC)[reply]

More, please?[edit]

Hi, I'm declaring myself a fan. Specifically your figure posted in Weinberg angle. It is a superb mnemonic on a messed up list of charge assignments I have had trouble making students I've taught the stuff to to appreciate. It is wonderful, and don't mind the pointless criticism of select fussers. For anyone familiar with the structure and its problems, it is greatly salutary. I have one quibble: In that article, your figure has little to do with the Weinberg angle, directly. Don't get this wrong, it is very useful where it is and it should be in more artices, basically because it is useful.

But... could you make one more for this article here, on the Weinberg angle? I have seen it in texts (T.D. Lee's book, p6 682 Search for "Weinberg angle"), and I teach it to my students all the time, and it helps.

I can describe it. It is a 30o right angle triangle, with the acute θ_W angle on the left; the base has g underneath it. Then the orthogonal side rises and it has g' to the right of it, labelling it. The hypotenuse has ${\sqrt {(g^{2}+(g')^{2})}}$ . From the right angle vertex, you also drop a "height" perpendicular to the hypotenuse, labelling it e, and might label its angle with the rising side as θ_W as well as the starting one. I could email you the figure if you wished. Anyway, I am convinced such a figure would be quite salutary for the article: a picture is worth a thousand words. Apologies for "farming work out", but i am not too competent with graphics...Cuzkatzimhut (talk) 20:58, 10 February 2017 (UTC)[reply]

For the record, Cuzkatzimhut has posted on my talk page. Will try to create something unless someone beats me to it. M ∧Ŝ c²ħε И_τlk 17:07, 20 February 2017 (UTC)[reply]

Drawing something now, think I have found the picture you're looking for on google books (fig 22.3 but on page 281?) M ∧Ŝ c²ħε И_τlk 08:31, 21 February 2017 (UTC)[reply]

Is this ok?

Let me know of any errors/improvements. M ∧Ŝ c²ħε И_τlk 08:55, 21 February 2017 (UTC)[reply]

Wow! Looks great. A helpful tweak would be skipping the unlabelled arc of the cosine-angle between the hypotenuse and g', and, instead, drawing the arc of the e-g' angle, which is also equal to the θ_W drawn, to remind the reader of the relationship between e and g'. But it's wonderful, anyway... Cuzkatzimhut (talk) 11:54, 21 February 2017 (UTC)[reply]

Made the change, I'll stop posting here now to prevent cluttering Cjean42's page. (Reason I have been posting here is because the description of the image and original request was here). M ∧Ŝ c²ħε И_τlk 17:40, 21 February 2017 (UTC)[reply]