Jump to content

Talk:Higgs boson: Difference between revisions

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
Content deleted Content added
Line 528: Line 528:
[[user:FT2|FT2]]&nbsp;<sup><span style="font-style:italic">([[User_talk:FT2|Talk]]&nbsp;|&nbsp;[[Special:Emailuser/FT2|email]])</span></sup> 13:10, 21 January 2013 (UTC)
[[user:FT2|FT2]]&nbsp;<sup><span style="font-style:italic">([[User_talk:FT2|Talk]]&nbsp;|&nbsp;[[Special:Emailuser/FT2|email]])</span></sup> 13:10, 21 January 2013 (UTC)
:They are not synonyms.--[[Special:Contributions/85.230.137.182|85.230.137.182]] ([[User talk:85.230.137.182|talk]]) 23:24, 2 February 2013 (UTC)
:They are not synonyms.--[[Special:Contributions/85.230.137.182|85.230.137.182]] ([[User talk:85.230.137.182|talk]]) 23:24, 2 February 2013 (UTC)
:As the ground state article says: "The ground state of a quantum field theory is usually called the vacuum state or the vacuum"...--[[Special:Contributions/85.230.137.182|85.230.137.182]] ([[User talk:85.230.137.182|talk]]) 23:45, 2 February 2013 (UTC)

Revision as of 23:45, 2 February 2013

WikiProject iconPhysics B‑class Top‑importance
WikiProject iconThis article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
BThis article has been rated as B-class on Wikipedia's content assessment scale.
TopThis article has been rated as Top-importance on the project's importance scale.

World Wide Computing Network

Reference #50 for a world wide computing network, with a link to distributed computing seems weird and inaccurate: from the reference

Poring over huge volumes of data, CERN physicists are confident they are now closer to achieving that aim, according to two scientists with links to two key research teams at facility, located on the French-Swiss border.

The scientists spoke of their CERN colleagues' progress after research chiefs at the facility decreed a cutoff last weekend in the processing of all data related to the search for the particle ahead of a major physics conference, the International Conference on High Energy Physics or ICHEP, which is scheduled in Melbourne next month.

Data still coming in after last weekend's analysis cut-off will be processed later in the summer. Physicists say that more than half of the collisions produce nothing of scientific value, and the record of their tracks are automatically dumped.

So, what part of this process, cited by the reference involves multiple computers? — Preceding unsigned comment added by 67.180.156.92 (talk) 06:26, 29 October 2012 (UTC)[reply]

Counter claim: This link shows a Beowulf cluster, specifically used for Particle Analysts:

There is about 4000 computer processing data of particle collisions. Sough of blower was quite loud.

http://www.youtube.com/watch?v=mPo9ud52Vs8 and

Cray X-MP/48 supercomputer at CERN. T450/0088

http://www.sciencephoto.com/media/349965/view "CERN reached a respectable 115th position in the TOP500 list released at the end of June. CERN's cluster, consisting of 340 servers with two Intel Xeon 5160 (Woodcrest) processors, with a total of 1360 cores, is one of only a few commodity clusters in the list. It reached a performance in the standard benchmark used for the TOP500 of just over 8.3 teraflops." http://cerncourier.com/cws/article/cern/30870

So, with three references, its obvious that both supercomputers and Beowulf clusters were available to be used for analysis, and not distrubuted computing. — Preceding unsigned comment added by 67.180.156.92 (talk) 06:56, 29 October 2012 (UTC)[reply]

You might want to look at [1].TR 07:08, 29 October 2012 (UTC)[reply]

Convermation of the Higgs Mechanism

In a recent change in the terminology section Useful background and terminology section

" which in turn will confirm that the Higgs mechanism takes place." was changed to "which in turn will confirm how the Higgs mechanism takes place." with the explination "that -> how (that it occurs isn't in question))". Yes it is the question there are other theories that generate mass. Finding the Higgs Boson would confirm the Higgs field is the correct mechanism for generating mass. The Higgs mechanism is the Higgs mechanism, finding the Boson doesn't add anything to it (except the mass may tell us why it isn't at the mass predicted by the Standard Model, but doesn't change the mechanism). — Preceding unsigned comment added by Dja1979 (talkcontribs) 01:56, 14 November 2012 (UTC)[reply]

The Higgs mechanism in nothing more than the explanation of how gauge bosons get mass after their symmetry is spontaneously broken. This mechanism makes specific predictions about the ratios of the masses, which were confirmed in experiments. The way is this mechanism is implemented in the Standard Model is just one of many possible ways, and pretty much all alternative mechanisms rely on the same Higgs mechanism. Hence FT's change.TR 07:27, 14 November 2012 (UTC)[reply]

Article streamlining

I was looking over the article.

During the first half of 2012, the problem was mainly that the article was inaccessible, poorly explained, and missed large chunks of central info. To fix it, a couple of overview and "simple explanation" sections were added. We still need some of these, but we've brought this topic quite a long way. The basic concepts are now much better explained (for this level of project) and also more exact and comprehensive. Now that we have figured (roughly) how to explain the topic, I think we could shortly re-condense and refactor, in order to reduce duplication that was once needed, and also to address incidents where the article contains multiple explanations of essentially the same background. We now know how to appropriately explain the Higgs boson, field and mechanism, so it doesn't need saying twice nearly as much.

I am not suggesting we do this "now" or "yet" but I am thinking we should do it at some point, and interested in feedback if people think it's possible. FT2 (Talk | email) 21:36, 19 November 2012 (UTC)[reply]

Deleted image by editor Cjean42

A few days ago, the editor Cjean42 included in this article (and in other related articles) a diagram that I subsequently deleted as I found it very unclear and bordering on WP:OR. A (civil ;-) discussion on Cjean42's talk page ensued:

Now I feel that the discussion has reached a point where it would benefit from the input of other editors. TR, FT2, anybody else who's interested, could you please have a look at it? What do you think about the disputed diagram? Cheers, Ptrslv72 (talk) 22:11, 2 December 2012 (UTC)[reply]

I've made an updated diagram that might be more clear. It's a plot of the weak hypercharge, Y, and weak isospin, W, of the Standard Model and Higgs field states, showing how the neutral Higgs (circled) determines electric charge, Q, at the weak mixing angle. One can also see in the plot, via charge conservation, how the neutral Higgs interacts, mixing the left and right fermion states to give them mass. This is a pretty minimal version of the plot. If you think it would be better, we could label the particle states, such as with eL and eR near the electron states, etc. Or we could add charges along any axis, such as 1/3, 2/3, 1 near the Q tics. Or add W and Y tics. But the more is added, the busier the plot gets, which is why I've used colors and shapes instead of labels. Or it might be better not to use these plots at all. Up to you -- they are a gift to Wikipedia. Cjean42 (talk) 23:41, 2 December 2012 (UTC)[reply]

Will look shortly, got 1/2 hr spare and I want to do the bit below in that time... FT2 (Talk | email) 09:05, 3 December 2012 (UTC)[reply]
Looked now. Deferring to Ptrslv72, I wouldn't immediately classify a diagram as original research. The question is, is the diagram helpful and something that particle physicists would agree on, and is it adding anything to user understanding on this article? If it is standard, then an example from a well known textbook would help, but even if it's a novel approach to a diagram, it can still be useful for an encyclopedia if, properly explained, specialists in the topic would agree it has explanatory value in the topic. (But if it does I am not seeing it right now, looks like a kind of modern art for all that I can see, certainly not the most intuitive presentation.)
My other additional concern is that this is already a substantial article, and possibly more will be added over time. If useful (which I can't guess), are there better articles for more detail on specialist areas, as Ptrslv72 suggests? FT2 (Talk | email) 09:40, 3 December 2012 (UTC)[reply]
Honestly, I think the proposed diagram is rather confusing. I don't quite see it being illuminating to any of our readers.TR 11:12, 3 December 2012 (UTC)[reply]
I wish I could take credit for this kind of weight diagram being original to me, but they date back to 1900 or so in mathematics, and to the 1930's or so in physics. (See isospin for similar diagrams.) On the most elementary level, it is a plot of the weak isospin charge and weak hypercharge of the four Higgs states, and all other Standard Model particles. As well as the information I described above, the diagram also allows a reader to infer all possible Higgs decays allowed by charge conservation. Any suggestions for making it less confusing? Particle labels maybe? Cjean42 (talk) 07:55, 4 December 2012 (UTC)[reply]

I see that Cjean42 has included in the article an updated version of his/her diagram. I think that: 1) this diagram would still look very obscure to the average reader; 2) it is not really necessary to provide the SU(2) and U(1) charges of the SM fermions in this article (moreover, there are no values on the axes, so the info is not even given in full); 3) the sentences in the caption "The four components of the Higgs field (squares) break the electroweak symmetry and interact with other particles to give them mass, with three components becoming part of the massive W and Z bosons. Allowed decays of the neutral Higgs boson, H, (circled) satisfy electroweak charge conservation." have very little relation with the actual diagram (I mean, where do you see that the Higgs breaks the EW symmetry and gives mass to the other particles?).

For these reasons, I would still remove the diagram from the Higgs boson article. Perhaps an amended version of the diagram could still go in the Weinberg angle article, after all it does show that weak isospin and hypercharge combine into electric charge. But what do the other editors think about it? Cheers, Ptrslv72 (talk) 23:44, 6 December 2012 (UTC)[reply]

The diagram is useful to readers because it matches the mathematical description in this section using a simple plot. You can see the charges of the four components of the Higgs field, and how these relate to the other particles according to their electroweak charges. These charges nicely summarize what the Higgs field is and how it interacts with other particles, seen in a visual way in this diagram, via charge conservation. To answer Ptrslv72's specific questions: The neutral Higgs, H, breaks the electroweak symmetry by specifying a direction in this diagram, with electric charge perpendicular to this direction. This same field, H, links the left and right handed fermion components, as can be seen by vector addition in the diagram, matching the mathematical description in this section. (For example, add H to uL to get uR.) You can also see the decays allowed by charge conservation, such as H -> uR + anti-uR. The information in this section is presented nicely for a reader in this charge diagram. I do think it's now less confusing, thanks to your previous input. I hope you agree and decide to keep it here. Cjean42 (talk) 01:05, 7 December 2012 (UTC)[reply]

The choice of symbols is a bit fanciful, but I can see how this electroweak charge plot would be useful to readers. If nothing else, it shows the Higgs boson as one of four components of the Higgs field. And, I'm embarrassed to admit it, but it did instantly remind me that the weak hypercharge of the Higgs field is 1, and not 1/2 as was here previously. -Dilaton (talk) 12:09, 8 December 2012 (UTC)[reply]

I don't see how the plot could remind you anything like that, since there are no values on the axes. Moreover, you should consider that the overall normalization of the weak hypercharge is a matter of convention (it's written even in the corresponding article). Some texts have Q = I_3 + Y, in which case Y_H = 1/2, others have Q = I_3 + Y/2, in which case Y_H=1. The quoted source in the last section, Peskin-Schroeder, uses the first convention, see eq.(20.69). Therefore, we should either stick to that convention or change the reference. Cheers, Ptrslv72 (talk) 21:14, 8 December 2012 (UTC)[reply]
Good point. But the important thing, which is what I was reminded of from the diagram, is that the Higgs has the same weak hypercharge and weak isospin as the left electron and neutrino. Maybe the lack of axes labels is to keep it convention independent. The Peskin and Schroeder convention conflicts with the one used in Standard Model (mathematical formulation), which is the one we should follow here, unless it breaks something. -Dilaton (talk) 23:19, 8 December 2012 (UTC)[reply]
We spent some time in the past trying to make sure that the section follows a self-consistent set of conventions (see the discussion here). I am hesitant to change it only to follow the Standard Model (mathematical formulation) article, which has inconsistencies of its own (see e.g. the kinetic term of the Higgs here). I'd rather stick to the PS convention and perhaps clarify it in the text. Cheers, Ptrslv72 (talk) 12:38, 9 December 2012 (UTC)[reply]
OK, that seems reasonable. -Dilaton (talk) 20:08, 9 December 2012 (UTC)[reply]

Merge from Higgs field

I merged in the article Higgs field and redirected. rationale is on that article's talk page:

from that page...
Merge to Higgs boson?

The article on the Higgs boson has been improved over the last few months, and is now a better quality description, including at lay-level, while this article seems poor quality with quite a bit of speculative WP:OR.

It doesn't need a separate "less technical" article now (or if it does then it is easy to modify that page for the purpose), which was part of the original motive for this page.

Also it's dubious whether a separate page is needed for a field and its quantum, given that this is a case where both are still strictly speaking, hypothetical.

Finally unlike longer known fields and their quanta, where we may have a lot more to say on both, there's little we can say about either of Higgs field or Higgs boson, that doesn't apply to the other, so there's a lot of redundancy.

On the basis any valuable sourced or useful content is retained, I'd like to merge these pages.

FT2 (Talk | email) 16:39, 1 December 2012 (UTC)[reply]

Totally agree. The opening is ludicrous ("In this context, the word "field" is used in the sense used in physics and not in the everyday sense"); the section "Overview" does not add anything to what is already in the main Higgs boson article; the section on "Inflation" is overblown, vague and contains inaccuracies; and the section "motivation" falls into WP:OR. For what I'm concerned, this article could simply be deleted. If some other editor is sufficiently familiar with the topic, he/she could add a small section on inflation to the main article. Cheers, Ptrslv72 (talk) 20:52, 2 December 2012 (UTC)[reply]

The sole useful content from that page - and even this would need checking for sources, balance and WP:OR - is best described as "Other speculation and discussion related to the Higgs field" - which is legitimate since it has evoked speculation both within the physics community and science writers, and elsewhere. The content that might be salvageable is:

possible salvageable content, to review?

[T]he Higgs mechanism is often credited with explaining the "origin" or "genesis" of mass.[1] But there is some doubt as to whether the Higgs mechanism provides sufficient insight into the actual nature of mass. As Max Jammer puts it, "if a process 'generates' mass it may reasonably be expected to provide information about the nature of what it 'generates' as well".[2] But in the Higgs mechanism, mass is not "generated" in the particle by a miraculous creatio ex nihilo, it is transferred to the particle from the Higgs field, which contained that mass in the form of energy, and "neither the Higgs mechanism nor its elaborations...contribute to our understanding of the nature of mass".[3] By coupling with this field a massless particle acquires potential energy and, by the mass–energy relation, mass. The stronger the coupling, the more massive the particle.

(Dubious value) - The way particles acquire mass through interacting with the Higgs field is analogous to blotting paper absorbing ink.[4] Pieces of blotting paper represent individual particles and the ink represents energy. Different particles "soak up" different amounts of energy, depending on "energy absorbing" ability and the strength of the Higgs field.

(Speculation of a wider cosmic role, inflation etc) -

The Higgs field has been proposed as the energy of the vacuum from which all else came. In the first instant of time, it had the featureless symmetry of an undifferentiated energy that all the universe was. In successive symmetry breakings at phase transitions occurring at discrete, lowering temperatures and densities, it gave rise to the universe. The last was the breaking of the electroweak force that liberated the weak and electromagnetic forces, and is now in reach of experiment. Well out of reach is the phase transition that separated the electroweak from the strong force. But the Higgs field, the proposed origin of all rest mass, is as central to investigation of the strong force as the weak.[5] The Higgs field has been postulated as a cause for inflation.[6] This is not part of the standard inflationary model, where the cause of inflation is left open. The name "generic" inflation has been suggested. The Higgs field is a "nonthermal" field, a field whose energy does not decrease as the universe expands. The higher the energy density, the faster the universe expands. So the large Higgs field is postulated as the cause of inflation. Above unification temperatures it is suggested that there was a single electronuclear force, and the bosons of the electroweak and strong forces were indistinguishable. As the universe's temperature dropped, it is thought the Higgs field caused the electroweakstrong force to fragment into the electroweak and strong forces and give separate identities to the electroweak bosons (photons, W and Z bosons) and the strong-force bosons (gluons). Eventually, even the energy of the Higgs field dropped to zero, marking the end of inflation.
Dark energy is postulated as an energy of the vacuum welling from the Higgs field.[7]
In the standard inflationary model the energy source for the geometrical fields in Einstein's equations are taken to be the physical vacuum energy-given by virtual particle-antiparticle pairs and radiation using quantum field theory. This 'vacuum energy' is taken to be the cause of the original expansion of the universe. [Alternatively, i]t is postulated that out of the initial quantum vacuum emerged a new sort of matter, different from ordinary matter in that it repels ordinary matter. This is postulated to be the Higgs field. The Higgs field decayed into ordinary matter, leaving the ordinary matter to continue in its expansion. This is the scenario that is meant to explain the presently observed expansion of the universe. There are several criticisms that have been applied to the generic inflation model, some of which apply to the standard model of inflation.[8]

One of the main motivations for postulating the Higgs field comes from the quest to find simple, symmetrical laws of nature.[9] Things fall down, not sideways. It required considerable effort to realize that the three dimensions of space are equivalent. Not until Galileo did people learn to "blame the earth" for hiding the simplicity of the principle of inertia. It was a good idea to formulate the basic laws of physics in empty space. Physicists are now convinced that empty space itself is a complicated environment. They "blame the vacuum" for many complications. Background fields permeate empty space. These fields hide the full simplicity and symmetry of physical laws.

Heat up a magnet and it becomes demagnetised. Its electrons do not recognize any special direction in space; the system is perfectly symmetric. But cool it down and the electrons align their spin axes due to forces between their spins. The perfect symmetry between the directions of space is destroyed through spontaneous symmetry breaking. Symmetric forces enforce an asymmetric solution. Physical laws are more symmetric than any stable realization of them. Physicists suspect that a similar effect is responsible for the background Higgs field permeating the universe. The answer to the question "Why isn't our vacuum more empty?" is that emptiness is unstable.[who?]

Just as the electromagnetic field is higher near heavily charged particles, the Higgs field should be higher near heavy particles. For instance, near a Z boson—an object that accelerators should be able to produce in great abundance in the near future—the Higgs field is changed. The Z boson is unstable. When it decays into lighter particles, the disturbance in the Higgs field must take on another form. It might become a travelling disturbance in the Higgs field itself—a packet of energy propagating outward-a Higgs boson. The Higgs particle is to the pervasive mass-generating Higgs field what the photon is to electromagnetic fields.

FT2 (Talk | email) 09:20, 3 December 2012 (UTC)[reply]

If this page is to cover the Higgs field as well as the particle, then there are some subjects that should definitely be discussed. These included but may not be limited to:
I wouldn't use any of the text of the old Higgs field article. Thinking about it, I am not entirely sure where to add this type of stuff to the current article.TR 11:32, 3 December 2012 (UTC)[reply]
There are a few "significant views", speculations and suggestions by scientists or popular writers that are probably worth a mention without being "crackpot" tiny-minority or "fringe", including some of these. I've slightly reorganized the last (media) section slightly to create space for these, unused as yet, but valid, to remind us to cover somewhat anyway. FT2 (Talk | email) 21:20, 3 December 2012 (UTC)[reply]
@TR I've had a go at covering at least the two scientific points you mention, but I'm hazy on them, can you correct? Thanks. FT2 (Talk | email) 19:52, 4 December 2012 (UTC)[reply]
I am not entirely happy with the (possible) physical significance of the Higgs field being discussed in a subsection of a section called "other public discussion". I think it may be a good idea to have a separate "physical significance" section somewhere near the beginning of the article. (Quite a few of the comments on this article have asked for this) This could cover (in one paragraph bits) the various ways in which the Higgs field/boson is physically relevant, possibly as a bulleted list. This should cover:
  • Breaking of electroweak symmetry/gauge boson masses. (quickly referring to the more detailed discussion of this elsewhere in the article.
  • Source of fermion masses.
  • Not the source of all mass. (Absorbing current note 3 and the first paragraph of "scientific discussion".
  • Higgs inflation.
  • Relation with the vacuum energie and cosmological constant problem.
Since this would be absorbing text from elsewhere in the article, this should not increase length by much.TR 10:24, 6 December 2012 (UTC)[reply]
Sounds a good idea, will bookmark this to have a go soon if nobody else does. FT2 (Talk | email) 04:10, 7 December 2012 (UTC)[reply]

Agency garden path

  • bosons, a type of particle that allows multiple identical particles to exist in the same place in the same quantum state
  • bosons, a type of particle that allows other particles to have mass

Physicists, of course, won't even notice the unintended reading.

MaxEnt 17:10, 4 December 2012 (UTC)[reply]

Thanks, but to me it's not clear what edit or even what sentence of the article you think could be improved. Can you be more explicit? Thanks. FT2 (Talk | email) 20:12, 4 December 2012 (UTC)[reply]

Length of the lead

The current lead of the article is too long. (see WP:LEADLENGTH) It needs to be condensed to 4 paragraphs at most.TR 15:08, 5 December 2012 (UTC)[reply]

It might benefit from attention - for example see comment on general article tightening above, and (as a first step) a proper "History of SM" article to allow the history to be condensed. That said the guideline is not as rigid as you suggest. Although the introduction says "no more than 4" the rest isuggests considerable doubt if this is intended to be rigid.
("The appropriate length of the lead section depends on the total length of the article. As a general guideline—not an absolute rule—the lead should normally be no longer than four paragraphs").
It's also a major and high profile article - perhaps there is none higher in physics this year - and the guideline suggests roughly a paragraph of intro might be sensible per 15k characters; with 4 paras up to 30k chars. This article is almost 15k longer, even excluding refs and "see also", which tends to support a view that the intro has to cover a lot to do its job:
("The lead serves as an introduction... a summary of its most important aspects... [that] can stand alone as a concise overview... many people only read the lead... should establish the context in which the topic is being considered by supplying the set of circumstances or facts that surround it...").
For these reasons can we leave the intro for a bit. If it's actually got obviously minor/superficial material, or can be condensed without loss, well and good. But right now it doesn't seem to. Its 5 paras are each concise and target important summary knowledge:
  1. What HB actually means/is, and where it fits into knowledge.
  2. HF link to HB, that HB would prove HF, that because of its importance it has been the target of an arduous search.
  3. Nonmenclature/name, including popular nickname
  4. Theoretical physical properties, if existent
  5. State of experimental search.
I agree with the intention and will see what can be done when it's tightened. But I don't think we can write an article that doesn't cover these. We can easily combine some of these for the sake of paragraph count, but readability matters more than count, given its prominence. FT2 (Talk | email) 04:37, 6 December 2012 (UTC)[reply]

History section (moved from TR's talk page)

I'm a bit concerned that the HB "History" section is more like a "History of the Standard Model". Not a surprise, as the history of the Higgs boson (and electroweak theory, Higgs mechanism etc) to a great extent is the history of the Standard Model or greatly overlaps it.

To fix this, much like the "search" section, a lot of this ought to be moved off to an article History of the Standard Model and summarized here. We have "history of..." articles for many aspects of physics but not for the SM itself. If we had such an article then this section could be (rightly) cut down a lot.

I've made a start at working on such an article here if interested and would like to ask for your help to keep an eye on it and suggest when it's at least capable of going mainspace. That way we can cut down the HB article history and link to that (new) article for the detail which would be good.

FT2 (Talk | email) 15:55, 4 December 2012 (UTC)[reply]

I think your concern is unwarranted. The history of the standard model is quite a bit broader than what is described here (and should cover the GIM mechanism, addition of a third generation, discovery of asymptotic freedom, color symmetry, proof that the SM is anomaly free only if the particles appear in a full generation, a more thorough account of the proof renormalisibility. The history section in this article quite adequately restricts to the history of the Higgs boson/mechanism. A History of the Standard Model article is a good idea, but I don't think that it should result in a much reduced coverage here.
There is probably some room for tightening things up. For example, we currently have a paragraph that tries to go into "what credit should go where" for the 1964 symmetry breaking papers. This can probably be condensed a bit, with details being left for the 1964 PRL symmetry breaking papers article. (The current depth of coverage of this aspect is at risk of having POV problems.)
As a whole this article does not have a real length problem. (Most high quality, high profile physics articles have a similar length.) It still has some issues with unnecessary duplication, which need tightening up, and should not grow much further, but the length in itself is fine.TR 09:45, 6 December 2012 (UTC)[reply]
I pretty much agree with all this, with a couple of points. Rigtht now the article goes into how the theory emerged in quite some depth. It covers the state of play in the 1950s, Yang-Mills,Anderson, the 1964 papers, Weinberg, 't Hooft and so on. All 100% relevant but I think if we had an article on the History of the SM, all we'd need to say here is something like this:

During the 1950s theoreticians had struggled because while gauge field theories seemed desirable and worked in other areas, when theories such as Yang-Mills were applied to a possible electroweak force and its symmetries, they failed, because they predicted particles and forces that clearly didn't exist. This was a result of Goldstone's theorem, which seemed to demand such particles would be created if symmetry was broken.

The theory of spontaneous symmetry breaking (Nambu, 1960), and the subsequent suggestion that the previous theoretical problems could perhaps be resolved this way if another field with an unusual but not impossible structure was involved (Anderson, 1962), led to three independent near-simultaneous papers in 1964 which together outlined a fully relevatistic theory for such a field, authored by Englert and Brout in August 1964, Higgs in October 1964, and Guralnik, Hagen, and Kibble ("GHK"). A formal description for the electroweak theory based on spontaneous symmetry breaking within a gauge-invariant quantum field emerged shortly after in 1967, when Weinberg and Salam independently applied these ideas to Glashow's incomplete electroweak interaction theory. Despite this progress, most of these proposals received relatively little attention at publication, quantum field theory being seen in the 1960s as a dead end; however the final piece of the puzzle, the proof of renormalization by 't Hooft and Veltman (1971), and promotion by Benjamin Lee, led to its widespread acceptance and retrospective recognition of many of the works involved as meriting Nobel prizes or other prestigious awards.

I think if we had a proper SM history article, that's all we need for history per se. Tightening up (see above) is good, but if the history of SM is that much more, then I might need some pointers what to include. If you're able to sketch that out quickly for me I'll have a go at getting something workable, if not perfect. FT2 (Talk | email) 15:45, 6 December 2012 (UTC)[reply]
Even though I was involved in writing them, I am in favor of condensing the paragraphs on "what credit should go where". Those paragraphs were the result of a very long discussion with an editor who was pushing some POV'ed statements from Guralnik's reviews without properly identifying the sources (read the archived discussion if you are patient enough). I have never been happy with the way we quote primary sources there - it borders on WP:OR - but back then this seemed the least-bad compromise. Later, I did not find it appropriate for me to alter the text that the other editor and I had agreed upon, but if you guys want to give it a try I will certainly not object. Also note that right now the article on 1964 PRL symmetry breaking papers is a real mess (check its talk page to understand what happened there). BTW, I wonder if the anonymous IP who is now attacking the sentence on Peter Higgs in the lead is just a new incarnation of the same old "Mary at CERN"... Cheers, Ptrslv72 (talk) 01:01, 7 December 2012 (UTC)[reply]

Background section

Not to be confused
Higgs mechanism The mechanism that explains why gauge bosons become massive when the corresponding symmetry is spontaneously broken.
Higgs field The field that break the elektroweak symmetry in the Standard Model.
Higgs boson The particle excitation of the Higgs field.

There is currently a lot of duplication between the Background and History sections. In addition the background section still suffers from being unreferenced. I think one we can deal with this, is by merging the Background section into the History section (Possibly renaming it "History and Background"). The current bullet points clarifying the terminology around the Higgs mechanism/field/particle are very useful. However, I think they would work better if they were condensed to 1-2 sentences, and presented as a float. Any thoughts or comments?TR 10:32, 6 December 2012 (UTC)[reply]

See #Article streamlining above, same thought.
I plan to work on this but need a History of SM article first, to avoid over-long and slightly off topic description of the rich theoretical background and histoiry involved - which is indeed substantial and on-topic, but needs to not dominate. Hence above. FT2 (Talk | email) 16:03, 6 December 2012 (UTC)[reply]

I have drafted a suggestion for a floating table to replace the terminology section on the right.TR 23:55, 7 December 2012 (UTC)[reply]

I like that approach. Needs a bit more but not much, but let me think on this, busy weekend, may be offline a bit. (add: HM="Believed proven", HF="The current preferred theory"). FT2 (Talk | email) 00:13, 8 December 2012 (UTC)[reply]
Out-takes from the redrafted "background":
The removed text, some material has been reused or simplified, review if wished

While there are several symmetries in nature that are spontaneously broken through a form of the Higgs mechanism, in the context of the Standard Model the term "Higgs mechanism" almost always refers to symmetry breaking of the electroweak field. Electroweak symmetry breaking (EWSB) itself is considered proven, and believed responsible for the mass of fundamental particles and also the differences between the electromagnetic and weak nuclear interactions which cease to be unified below a very high temperature of about 1015 K. But the exact cause has been exceedingly difficult to prove; the lack of adequate data in this area has also limited the development and testing of more advanced ideas.

The leading and simplest theory is that a particular kind of unseen "energy field" (known as the Higgs field) exists throughout the universe, which - unusually - has non-zero strength everywhere. This kind of field was shown in the 1960s to be theoretically capable of producing a Higgs mechanism in nature, and particles interacting with this field would acquire mass. During the 1960s and 1970s the Standard Model of physics was developed on this basis, and it included a prediction and requirement that for these things to be true, there had to be an undiscovered fundamental particle as the counterpart of this field. This particle would be the Higgs boson (or "Higgs particle"), the last unobserved particle of the Standard Model. The Higgs boson's existence would confirm this part of the Standard Model and allow further development, while its non-existence would confirm that other theories are needed instead.

This does not change what you have said - and I agree - that there is redundancy. But at least the background is able to be more accessible for non technical readers. FT2 (Talk | email) 17:35, 12 December 2012 (UTC)[reply]

Fact check on Yukawa coupling?

In the Higgs mechanism, it's clear that 3 HF components are absorbed and the fourth is realized as the Higgs boson.

In Yukawa coupling in the same context, does the same happen (3 couple and 1 is realized as HB), or do all 4 couple and HB is not realized in this interaction?

If the latter can someone (TR?) correct my intro edit to read something like: One of two processes can occur. Three of the components of the Higgs field are then "absorbed" by the SU(2) gauge bosons (the "Higgs mechanism") and the fourth component very briefly becomes a Higgs boson, or else all 4 components couple to fermions (via Yukawa coupling), in both cases causing these elementary particles to acquire mass.

Thanks FT2 (Talk | email) 02:43, 8 December 2012 (UTC)[reply]

I've tried to make the relavent paragraph more complete and precise. All four components do couple via Yukawas, but only one gives mass. -Dilaton (talk) 07:37, 8 December 2012 (UTC)[reply]
Thanks, and welcome. I have 3 more edits on the intro (mainly duplicated information), if you can see a quick fix please go for it.
  • 1st and 4th para duplicate a sentence:

    1st - It [the Higgs field] would also confirm how fundamental particles acquire mass, open doorways to completely new knowledge, and guide future theories and discoveries in particle physics, and may shed light on a number of other research topics.
    4th - If confirmed, proof of the Higgs field and evidence of its properties is likely to greatly affect human understanding of the universe, validate the final unconfirmed part of the Standard Model as essentially correct, indicate which of several current particle physics theories are more likely correct, and open up "new" physics beyond current theories.

    Can you figure which is the better combined wording, update the 1st para, and remove from the 4th para (leaving the 3rd para much shorter). I think the final sentence about "if the Higgs field doesn't exist" should stay where it is though, to stop the 1st para getting too long and hard for readers.

  • 1st para contains a technical sub-clause ("the Higgs boson-a particle that is the field's smallest possible excitation") which duplicates twice in the 3rd para ("The Higgs particle is a quantum excitation of one component of the four component Higgs field" ... "Quantum excitations of this fourth component are the short-lived Higgs boson"). If this was removed from the 1st para and merged into the 3rd para, then the 1st para would be much easier for readers ("...a decades-long search for the Higgs boson, and also...").
  • Re-check on your 3rd para edit (see original question above). As it now reads, the 3rd para implies one single process and not two independent processes. In other words it implies that 3 field components absorb into gauge bosons giving them mass (correct) and simultaneously or as a result (dubious) the 4th component also couples to fermions giving them mass (with any quantum excitations of the fermions being what we detect as the boson).

    That's surely not what is meant for 2 reasons: 1/ it implies the gauge bosons couldn't be massive unless fermions happened to also be present, 2/ sources all say that the 4th component is realized as the Higgs boson (presumably whether or not fermions are present and independent of any Yukawa coupling), not that the 4th component couples to fermions and it is fermion excitation that we detect as the Higgs boson. I think if these are indeed two completely independent interactions (Higgs mechanism->gauge bosons and Yukawa coupling->fermions, with the Higgs boson realized in the 1st case only, or both) then we need to be clearer on that point.

FT2 (Talk | email) 09:47, 8 December 2012 (UTC)[reply]
It is the fourth component of the Higgs field that also couples to the fermions via Yukawas and gives them mass. But they don't need to absorb Higgs components like gauge fields do when they become massive, so this one neutral Higgs component can do the job for all. And the fermions do not form the Higgs boson. The Higgs boson is a small quantized excitation of the neutral Higgs field component on top of its constant zonzero vacuum value. -Dilaton (talk) 10:59, 8 December 2012 (UTC)[reply]
Had a go at revising the lead. -Dilaton (talk) 11:55, 8 December 2012 (UTC)[reply]

The image http://en.wikipedia.org/wiki/File:Elementary_particle_interactions.svg suggests that the Higgs field also couples to neutrinos in the SM, this is not true since the Yukawa interaction requires coupling to a left handed (weak) isospin doublet and a right handed singlet - if I'm not mistaken. The image also indicates a copuling of the photon to neutrinos, which can't be due to lack of electric charge. 92.201.63.113 (talk) 17:22, 11 December 2012 (UTC)merualhemio[reply]

As I remember, coupling to neutrinos arises from terms that contain charge conjugated fields. Ruslik_Zero 18:47, 11 December 2012 (UTC)[reply]

The second coming of the God particle

http://www.theregister.co.uk/2012/12/16/second_higgs_spotted/ There appears to be not one Higgs boson “signal”, but two: one at 123.5 GeV (giga-electron volts), the other at 126.5 GeV. The first decays into pairs of Z particles, while the second shows the decay of a Higgs into two photons.

Is the 123.5 number solid enough to note? Hcobb (talk) 01:51, 17 December 2012 (UTC)[reply]
Not really. It are preliminary results from one (of the two experiments), where there is still significant overlap of the 2 sigma uncertainty. So, unless CMS finds something similar, and both experiments feel confident enough to actually publish these results, I do not see any reason to remark on it here.TR 09:45, 18 December 2012 (UTC)[reply]
The fun part isn't the barbell shape. It's that the two different decay modes point to two different masses. Hcobb (talk) 13:05, 18 December 2012 (UTC)[reply]
For reference, a number of sources say it's expected to be a measurement anomaly or artifact, rather than a verified double-Higgs. Minimum mention only, if any. FT2 (Talk | email) 15:44, 3 January 2013 (UTC)[reply]

Patent nonsense

I see FT has restored his nonsense distription of the Higgs mechanism:

It is believed that the electroweak interaction (one of a few universal forces) usually "divides" into two very different forces which act on different particles (electromagnetism and the weak force). This is known as 'symmetry breaking'. Nobody knows for sure how it happens. Finding the answer would be monumental to human knowledge and physical science (see 'Significance' below).

The "Higgs mechanism" describes how physicists think this might happen in nature. If a specific kind of energy field happened to exist in nature, then any massless particles created when symmetry breaks "absorb" energy from the field to become massive. The two forces differ because particles responsible for the electromagnetic force (photons) remain massless, and can travel and act over immense distances, but particles responsible for the weak force gain mass, and can therefore only travel an extremely short distance before they break apart.

Lets pick this apart line for line:

  • It is believed that the electroweak interaction (one of a few universal forces) usually "divides" into two very different forces which act on different particles (electromagnetism and the weak force).
    • "usually"? It sometimes doesn't? Very misleading.
    • Act on different particles? For the most part, the electromagnetic force and weak force act on the same particles, with just a few exceptions (like neutrino's). So, again a very misleading statement.
  • This is known as 'symmetry breaking'.
    • No it is not. Symmetry breaking is not the converse of unification. Electromagnetism and the weak force and the weak force are different because part of the symmetry is broken and another is not. Symmetry breaking occurs in all sorts of situations, most of which have nothing to do with forces.
  • The "Higgs mechanism" describes how physicists think this might happen in nature.
    • This is not the point of the Higgs mechanism. The point of the Higgs mechanism, is that spontaneous symmetry breaking of gauge symmetry leads to mass gauge bosons. i.e. the weak force being short ranged.
  • If a specific kind of energy field happened to exist in nature,
    • There is no such thing as an "energy field". Well, you could make sense of the term as describing an energy density, such as the electomagnetic field energy. The Higgs field certainly is not such a field. It is not helpful too lay readers if we throw out esoteric sounding but totally meaningless terminology.
  • then any massless particles created when symmetry breaks "absorb" energy from the field to become massive.
    • No. No. No. 1) Goldstone bosons are not created when a symmetry breaks. 2)In the Higgs mechanism, the Goldstone bosons do not become massive. First of all there are no Goldstone bosons in the Higgs mechanism. The would-be Goldstone bosons in the Higgs mechanism become the longitudinal parts of the W and Z bosons, changing them from massless/transverse spin 1 particles to massive spin 1 particles with three polarizations.

As you see, I had some very good reasons to rewrite this bit of gibberish. Lets just focus on basics that anyone can understand "The Higgs mechanism explains why the weak force has a short range." Instead of the esoterich bull crap that is currently there. (end of rant mode, sorry for the harsh language)TR 10:31, 18 December 2012 (UTC)[reply]

The article needs to cover carefully its technical and background information. I added the "math" and a bunch of theoretical material so you know that we agree on that. But you need to appreciate that 90%+ of readers will not be able to understand even what you see as a simple explanation. This part needs to be much simpler than even you imagine, but yet it needs to explain the concept properly. You know physics, but I am worried that you don't yet fully appreciate the need to give simple (and simplistic) explanations for those who don't have that background, or you see it as so important to be precise that you ignore the 90% it would marginalize. Look at the feedback to see if I'm exaggerating. An unacceptable proportion say they find even the simple versions we've had, too complicated.
With that let's respond on your comments on mine, then my comments on yours, and see if we can find ways to bridge the gap.
Comments on your dissection above, and why I disagree
  • Yes, the electroweak does "usually" divide. At sufficiently high energies (which can and do probably exist in the universe today) it is one undifferentiated interaction. So it is not "always" the case. "Usually" is a simple way to explain that there may be circumstances of sufficient temperature for this not to happen.
    (I'll intercede my comments on this here if you do not mind) Even if the symmetry is not broken the elektroweak interaction still breaks up into two forces. (Because the symmetry group is not simple.) Also see comment below.TR 15:16, 18 December 2012 (UTC)[reply]
  • "Act on" - should have been "act through", typo.
  • "This is known as symmetry breaking" - perhaps "this is an example of symmetry breaking" would be better. Basic idea is correct. They differentiate in manifestation, and that's because symmetries are broken. Simple version - Scientists believe that differentiation results from symmetry breaking. They want to confirm what makes EW symmetry break, and whether HF is responsible as suspected.
    There is some misconception in you thought on what symmetry breaking is. Symmetry breaking has nothing to do with the weak and EM forces being separate. This already contained in the fact that there are two symmetry groups before symmetry breaking (U(1) and SU(2)) each with its own coupling constant. Symmetry breaking simply explains why the effective Lagrangian of the broken theory can contain terms which are not symmetric under the full symmetry group. This misconception seems to be at the heart of your piece failing to be sensical.TR 15:16, 18 December 2012 (UTC)[reply]
  • At a simple level statement is correct. The HM is how we think EWSB happens. Therefore HM is how we think the electroweak comes to have two different manifestations in the everyday world, and why some particles (gauge bosons, but we don't need to say that technical term here) have mass.
    No, the HM is not "how" we think EWSB happens. Its a description of "what" happens if EWSB happens.TR 15:16, 18 December 2012 (UTC)[reply]
  • To call the Higgs field a "kind of energy field" is simplistic but at this level appropriate. It is a field; particles gain energy (in the form of mass) from interacting with it. So it's easy and understandable. A technical reader can find a more precise version below.
    No, it is never appropriate to use a technical sounding term, that has no technical meaning. This is basically blowing smoke up the readers ass. Note, that this is not simplistic, but simply meaningless. ("energy field" is not any simpler than "fundamental field"). TR 15:16, 18 December 2012 (UTC)[reply]
  • Last point you raise is capable of improvement but basic description is appropriate. In the absence of HF, theory says that symmetry breaking would lead to massless particles. These particles do not arise as massless because they absorb components from the field. How do we explain that simply? The particles which arise acquire mass. That mass was originally potential energy. So at a simple level, we can explain that some bosons would otherwise arise as massless - hence the theoretical problem - but SM says that if HF happens to exist, they would instead arise as massive and not massless, and that is because they will absorb energy from HF (via 3 components and a process described later which we don't need to say here).
    What you say here is simply incorrect. 1)Theory does not say that symmetry breaking leads to massless particles in the absence of the HF. The goldstone theorem says that if a symmetry is broken that there must be a massless scalar for each broken symmetry. However, the Goldstone theorem does not apply to gauge symmetries. 2) Theory does say that if the gauge symmetry is not broken the gauge bosons must be massless. 3)The would be Goldstone bosons are the massless components of the Higgs field (not the massless gauge bosons!). You seem to get these mixed up.TR 15:16, 18 December 2012 (UTC)[reply]
Time to pick the rewrite apart. Sorry for the tone, but it's important you get the need to greatly simplify at least in this section, and understand how lay readers will read your words.
  1. "The Higgs mechanism explains why the particles transmitting a force become massive" - all of them do not. Misleads them to believe all force carriers are massive.
  2. "if the symmetry governing the force is broken" - if symmetries are laws of nature, how can they be "broken"? (doubtful we should go into how they aren't "really" being broken, it just looks that way, at this level)
  3. "[HF] does not obey all the symmetry laws of the model" - if symmetries are laws of nature, how can they not all be "obeyed"?
  4. "causing it to differentiate between the electromagnetic and weak force" - I probably get nothing from this (as a lay reader), right idea, but too hard a wording for many lay readers.
  5. Proposed HM description is a classic mistake of "does not answer the question". The question is "what is the Higgs mechanism?". The text proposed answers this by saying "HM explains why particles acquire mass when laws of nature are broken" (sorry but that is how it reads) and then recaps the effects of EWSB. It doesn't speak to the actual question. It doesn't explain what HM is. It palms the reader off by saying "it's the label for whatever does EWSB" and describing the effects of EWSB. Relevant but not speaking to the question.

    What is the Higgs mechanism? It is a mathematical proof that if you 1/ have a gauge field theory and 2/ you feel symmetry breaking is needed to explain one interaction manifesting as two and the existence of mass, but don't want the theory to predict new massless particles, THEN, 3/ if an extra field of a specific kind happened to also exist, it would in theory 4/ modify the "usual" symmetry breaking process, so that instead of new massless particles we get a kind of combo deal leading to expected massive ones.

    Put that in non-technical terms and we'll be answering the question.

Sorry to be harsh in tone, TR, it's not 'you' or 'me' as much as a difference in concerns. I feel strongly there is a great tendency to pitch this difficult topic at too high a level, and this one section must avoid that. We have synergized our approaches well generally, and we will here as well. We can provide more exacting explanations below for other readers. But a lay reader has to be able to get the basics and this section is their hope of it. FT2 (Talk | email) 13:13, 18 December 2012 (UTC)[reply]
Responses to your responses:
  1. All force carriers that correspond to broken symmetries are massive, the ones that correspond unbroken symmetries are not. This exactly what the second part of the sentence that you omitted to quote says. We should be able to assume that readers are able to parse conditional sentences.
  2. The same can be said if you just say "symmetry". (How can something be a symmetry if it is broken?) The concept that nature breaks its own laws is somewhat essential to what is going on. Put I am open to better descriptions of what a symmetry is in in laymans terms.
  3. idem
  4. I am not sure what is real hard about the wording here. But I agree that this can still be phrased better. (But at least it is not nonsense.)
  5. It might be better to say that "the HM is the explanation why ..." (Also again note that symmetry breaking is not "one force manifesting as two", that has nothing to do with it.) If read in that way (in which it was intended) it does answer the question what is the Higgs mechanism. Note that the Goldstone theorem suggesting that there must be massless particle if a symmetry is broken, was an historical red herring resulting from physicists ignoring the mathematical fine print. The HM is simply a counter example to the theorem if not all of its conditions are met. There is no need to go into historical mistake at this level of discussion. (Mentioning a massless goldstone bosons just leads to confusion as your piece aptly demonstrated.)
I think that the thing that you do not realize, is that the description that you gave was not simple at all. It was needlessly being complicated by introducing vague terminology that did not quite mean anything (like "energy field"). It is not helpful to lay readers to present them with a text that sounds like they should be able to understand it, but in the end do not because it does not really say anything.
The text I pitched isn't really any more difficult to comprehend, but is a lot more too the point.TR 14:52, 18 December 2012 (UTC)[reply]

I think we understand each other here and have a lot of common ground, we should be able to handle this like others in the past. But doing it by revert on the article page is unsightly. What I'd like to ask is, suppose we collaborate here on figuring out a single (jointly edited) bullet list of what we need to say and how to say it, and discuss points as needed. I was drafting what I thought, to start it, then I realized perhaps I se where the problem is. Try this:

We have a table of 3 explanatory boxes (HM, HF, HB). The HM is the context for HF, and HF the context for HB, so it's easy for a reader who's read one, to "get" the following, and easy for us to keep them short. I think we may have missed one box though. There is a zeroth box, briefly describing EWSB. That's the context for HM (i.e. should be EWSB -> HM -> HF -> HB). It's why my HM version has 2 paragraphs and yours one, and why the HM section is being difficult. The HM paragraph is trying to explain not only HM, but also the underlying context within which HM makes sense, as meaningful background, namely EWSB and symmetries. Because HM doesn't make sense without these, it's not able to skip them in explaining HM.

Can you have a go, maybe add a prior short EWSB paragraph, and see what that does. It only has to explain a little, in simple terms. Some key points might be these:

In the world around us, the fundamental EW force manifests as two very different forces (EM + W), In understanding why this is, we find it has both massive and massless force carriers, making the different force carriers and the interactions they mediate behave very differently. Theory suggests that (if gauge invariance is kept) something else must be causing some of the EW force carriers but not others to acquire mass, because if not then we would find other massless particles, and we don't. It's believed the massive particles result from a process called "symmetry breaking". But nobody knows how symmetry breaking is triggered or exactly what happens. It's potentially very significant if we find out.

HM then picks up from there, which makes it much simpler.

HM is a theory (or model, or a proof that an idea is possible) which shows if a field exists of a specific kind, it would have this exact effect. The field would both break symmetry because of its unusual 'shape', and then interact further with the breaking symmetry, causing the expected massive particles (carrying the weak force) to correctly arise, but leaving others (specifically the photon carrying the EM force) massless, and not giving rise to any unexpected massless particles.

We can keep the HM paragraph short, because we've explained EWSB and other more basic principles and context in the prior paragraph, keeping it simple. (I had used the term "divides", as a simple term that conveys "manifesting as two distinct forces" to most lay readers. I think the above is easier, if accurate. Of course it's correct to say "has its symmetry broken", but we need to remember this can be quite intimidating "jargon" to many users)

Hope I got the technical details roughly right, if not please excuse and correct. FT2 (Talk | email) 19:12, 18 December 2012 (UTC)[reply]

This is at least somewhat better, although it is still a bit confused about what the HM is. This is manifested by the sentence "It's believed the massive particles result from a process called "symmetry breaking"." The HM simply is the statement (or maybe its mathematical explanation) that symmetry breaking (of a gauge symmetry) leads to massive gauge bosons. In this sense, the split you make doesn't quite make as much sense.TR 07:37, 20 December 2012 (UTC)[reply]

Sorry, I read the discussion above very quickly because I am currently busy with my own work, but in general I sympathize with TR's point of view: we should not make incorrect statements just because they sound simpler to grasp in one non-expert editor's head. They will still sound abstruse to most other non-expert readers, and on top of that we will be left with a nonsensical article. Formulating statements that are at the same time correct and accessible to the lay readers is of course quite difficult even for the experts, but it becomes almost impossible without a solid understanding of the topic. I am sorry to say this, but somtimes I have the impression that FT2 - well-meaning as he/she may be - lacks that necessary understanding. For example, in the discussion above FT2 keeps repeating things such as 'It is believed that the electroweak interaction (...) divides into two very different forces (...) This is known as symmetry breaking". TR has tried several times to explain that symmetry breaking has nothing to do with the fact that the EW interaction divides in two forces. In fact, there are two fundamental forces to start with, i.e. those associated with the SU(2) and U(1) gauge groups, respectively. The effect of symmetry breaking is that a combination of those two forces, i.e. the weak force, becomes short-range (while the rest, i.e. the electromagnetic force, remains long-range because the breaking of the symmetry is only partial). However, this explanation appears to go over FT2's head, and he/she keeps repeating his/her own flawed interpretation until the very end (see "the fundamental EW force manifests as two very different forces (EM + W)"). It would really be a pity if, as a result, TR became discouraged and gave up improving the article... This said, I apologize for not participating more constructively in the discussion, but as I mentioned above I really don't have time now. Cheers, Ptrslv72 (talk) 16:49, 20 December 2012 (UTC)[reply]

P.S. this example may help dispel FT2's confusion: consider a hypothetical situation in which the ground state breaks U(1)_EM too. In this case, the "weak" and "electromagnetic" forces would not look so different (both would be short-range, mediated by massive bosons), but the EW symmetry would be more completely broken than in the Standard Model. It should then be clear that "symmetry breaking" does not correspond to the fact that the weak and EM forces look very different from each other. To suggest that this is the case (as the lead still does) is a disservice to the readers. We offer them a picture that seems easier to digest, but in fact is incorrect. Cheers, Ptrslv72 (talk) 21:47, 20 December 2012 (UTC)[reply]

No apologies needed. I've made no bones of it, I'm not a particle physicist, but I do have what's needed to understand enough, and I can help it end up in terms that others can as well. But I'#m not a mathematician or physicist so yes, I am reliant on you both (and others) for technical hawk-eyes and catching my own misunderstandings. Hence why I might at times have said I disagree, but have listened and tried to find where differences arise and reconcile them, learning as the article improves.
I echo Ptrslv72's comment - and TR, in no way at all be discouraged. It is a complex topic, but the whole of Wikipedia develops by people of different skills together, and if you look at the article - for which I've had to educate myself on everything from "what is a symmetry" to "how did we get to Yang-Mills, Nambu, Anderson and PRL and from there to Weinberg, 1972 and eventual acceptance", missing sections, and the search and naming of the topic... I think anyone would agree I've acquitted myself well. But I'm no physicist and will never be, hence my urging to "excuse and correct" any technical misunderstanding and do it here on the talk page which is more relaxed.
An acid test. I'm above average competence for a non-physicist. To the extent I don't understand a point, the article is too high level for any but technical readers, and that's evidence not for discouragement, but for figuring what's confusing and how to improve it. I need to learn physics "enough". Physicists need to learn "lay person level explanations". Together we have done it, and if it's taken a while for me to learn enough, all I can say is thanks, it has done wonders for the article jointly, and above all do be encouraged that it is getting good :) But it has to be done some way or another, or the article can't do its job.
Thanks for this Ptrslv72. I hope this is ok in your eyes and TR's both - and anyone elses! FT2 (Talk | email) 21:52, 20 December 2012 (UTC)[reply]

Lead section

I propose the lead section should be shortened and should adhere to WP:ss , the article feedback generaly indicates that the lead is too long for most people and that they would like a summary as lead. — Preceding unsigned comment added by Hybirdd (talkcontribs) 23:27, 27 December 2012 (UTC)[reply]

This was discussed recently (see #Length of the lead) and is worth thinking about. But it is a substantial and high profile article. The article's overall length was discussed somewhat above - comment by TR was
"As a whole this article does not have a real length problem. (Most high quality, high profile physics articles have a similar length.) It still has some issues with unnecessary duplication, which need tightening up, and should not grow much further, but the length in itself is fine.".
The lead was also discussed. The issue is, it does have to cover a lot, and it cannot do it in a style that loses the lay reader. That section summarizes what it has to cover. Now we have figured how to say it more simply, if there is room to trim then go for it, but I suspect the intro length is in fact appropriate to the article contents and difficulty. To me, the feedback says we used to get a lot of issues with "too complicated". Now we're not really getting that so much, and there isn't much recent comment on lead length (these changes were a couple of weeks ago). $0.02 thoughts on it, but if the lead has "puff" then that's something to address. Do you see much? FT2 (Talk | email) 13:50, 28 December 2012 (UTC)[reply]
To help I'd suggest cutting the paragraph dealing with its name to just "The Higgs boson is named after Peter Higgs, who—along with Brout and Englert, and with Guralnik, Hagen, and Kibble ("GHK")—proposed the mechanism that suggested such a particle in 1964.[11][12][13] Higgs was the only one who emphasised the existence of the particle and calculated some of its properties." And then move the rest (God particle, why it's disliked etc) to either a "Name" section or other area. Coinmanj (talk) 00:16, 30 December 2012 (UTC)[reply]

In the popular media, it is being reported as fact that the Higgs boson has been discovered and its existence confirmed. Consider this NPR story, with its caption saying "Scientists at the Large Hadron Collider announced the discovery of the Higgs boson on July 4, the long-sought building block of the universe." Should such statements go unchallenged or unreported in this article? BecurSansnow (talk) 23:06, 1 January 2013 (UTC)[reply]

The only way we could include a discussion of these statements, if we can find proper secondary sources discussing the statements in the popular media. Without those, we should stick to statements which can be sourced to reliable sources, and for this subject (and science in general) the popular media certainly do not qualify as reliable. But if somebody can drum up a reliable secondary source that discusses the inaccuracy of the media coverage of the Higgs boson, then we should certainly have a (small) section on this.TR 10:44, 2 January 2013 (UTC)[reply]

Something like this, as a subsection to "non technical overview" maybe?

=== Higgs misconceptions ===

A number of misconceptions about the Higgs boson have entered popular myth. Examples include:[10]

Myth Reality
The Higgs boson (or particle) has been discovered. A previously unknown particle has been proven to exist. It is not confirmed in any way whether or not it is actually a Higgs boson, or some other kind of new particle (although many people believe the former).
There is only a 1 in (some number) million chance the Higgs boson does not exist The 1 in millions figure (which changes over time) relates to the discovery of a particle. It does not say how likely that particle is to be a Higgs boson at all. (Technically it represents the chance that random background processes made it look like this particle exists, when it does not.)
The Higgs boson creates the Higgs field This is the wrong way around - if the boson exists, then the Higgs field would be the reason the boson exists.
The Higgs boson is responsible for all mass. The Higgs field (and not the boson) would be responsible for the mass of a number of fundamental particles. Even so, that would still only be a small part of all the mass we see around us.
The Higgs field is kind of space-filling medium, a bit like the aether. The Higgs field - if it exists - would be a quantum field that exists throughout space and pervades space, but it is not a substance, and cannot in any sense "fill" space. (A naive and simple analogy is that of gravity or the earth's magnetic field, which pervade but do not "fill", and can be detected by their effect on other particles).

FT2 (Talk | email) 15:03, 3 January 2013 (UTC)[reply]

Such things are generally considered unencyclopedic.TR 15:48, 3 January 2013 (UTC)[reply]
On a quick check this is quite common:
and a lot more...
I'd say rather, it's encyclopedic, but (as you said) is there enough coverage of these kinds of issues, to support a section noting them? If not then the material is still useful in an educational sense, can we check these points are sufficiently clear and sure, for a reader? FT2 (Talk | email) 16:04, 3 January 2013 (UTC)[reply]
Note that none of those articles is GA or FA class. Also note that almost all those sections are poorly sourced.TR 07:47, 4 January 2013 (UTC)[reply]
GA's (with good sourcing) too, where applicable to the topic:
It's hard to create a search for these, as there isn't a "search within GA/FA" function. Those FAs I could find, had fewer to cover and perhaps for this reason tend to state them inline ("It is a common misconception that..."). FT2 (Talk | email) 11:33, 4 January 2013 (UTC)[reply]
WP:NOTTEXTBOOK applies here. A list of common misconceptions in effect is a mixture of points 5 and 6 mentioned there. The purpose of Wikipedia is to inform rather than to teach. Clearing up misconceptions is not WP's purpose. Rather we should present the information in such away that it does not repeat any misconceptions.TR 13:37, 4 January 2013 (UTC)[reply]

Range vs. Mass

The article contained a bogus explanation of why forces with massive gauge bosons have a short range. (I think I may have made the mistake first.) Unlike what was stated in the article this has nothing to do with the gauge bosons decaying. (It is fairly easy to construct a model with massive gauge bosons which are stable.) Instead it has to do with the fact that, massless boson can have any wavelength, while the wavelength of a massive boson is limited by its rest mass. For an detailed explanation see [2].TR 10:39, 2 January 2013 (UTC)[reply]

That's brilliantly helpful and clear, and a good source/explanation too, thank you. One thing, I think we do need to reinstate the short sentence that symmetries can be broken by natural processes, because it's too big a jump otherwise from "symmetries are laws of nature" to "symmetries when broken can cause XYZ". We don't need to say much here, it was 10 words only - just that they can be broken by natural processes. Also the .com link seems to work where the .nl doesnt? FT2 (Talk | email) 15:10, 3 January 2013 (UTC)[reply]
One of my intentions was to avoid phrases referring to "symmetry breaking". "Symmetry breaking" is a type of jargon that does not mean much to the general reader. Instead I opted for just stating what is meant by a symmetry breaking directly, i.e. there exists a field that does not obey the symmetry rule. (Of course, strictly speaking it should be "whose ground state does not obey the symmetry rule", but that would be a bit too technical I think.)TR 15:59, 3 January 2013 (UTC)[reply]
Makes sense, and that clarification might be useful.... work here, I'll give it a bit of thought later. FT2 (Talk | email) 16:06, 3 January 2013 (UTC)[reply]

Technical question on symmetries

We state at the moment that it is possible for symmetries not to be followed (or "obeyed"). I've never been too happy with that phrasing, though "not followed" is at least bearable. I'm a bit hazy on this but would it more accurately describe the situation, to say instead that other processes can cause symmetrical laws to produce asymmetrical outcomes? (this was the description in one paper on HM and seems to match most descriptions of what HM actually involves) If not, in what sense is it "not obeyed" rather than something else? And is it just one symmetry that HM breaks in SM, or 3? FT2 (Talk | email) 23:56, 9 January 2013 (UTC)[reply]

In general, a symmetry is broken if there is some element of the theory that does not comply with/obey (follow seems a very strange term to me in this context) the symmetry rules. For example, the CKM matrix is not invariant under CP symmetry and consequently the CP symmetry is said to be broken. Similarly, the fact that the electroweak interaction couples differently to left- and right-handed particles breaks parity (P) symmetry (but not CP).
More specifically, a symmetry is spontaneously broken if all the equations of motion comply with/obey the symmetry rules, but the lowest energy solution does not comply with those same rules. The classic example of this is a ferromagnet. If you ignore any effects of the atomic structure, the equations of motion for the magnetic field in an infinite ferromagnet are invariant under rotations. However, in the ground state of the system all magnetic domains point in the same direction, a state which clearly is not invariant under rotation. (Although rotation will produce another ground state, which is also typical for spontaneously broken symmetries.) This is also what happens in the Higgs mechanism. The equations of motion obey the electroweak symmetry, but the ground state of the field breaking the gauge symmetry does not.
Do we want to be more precise, than the current phrasing. I'm not sure. Trying to be more precise seems to lead to an uncanny valley of vagueness. The phrase you suggest for example, is trying to make a rather precise statement using very vague terms (process, outcome) making it rather useless to most readers. (For lay readers it is trying say something to complicated, for more technically schooled readers it is too vague to make sense of.)
I think for the majority of readers it does not make much difference whether a symmetry is broken explicitly of spontaneously. Since there is no conceptual understanding of the difference between equations of motion and their solutions. At this level of exposition this difference is not that important either. (We become a lot more explicit later in the article)
To your last question. That is a matter of how you count. There is one symmetry group that is broken, however that group had three generators. This is one of these things that becomes ambiguous once you become less precise. (It is the same question as asking how many symmetries are broken by the ground state of a ferromagnet.)TR 10:47, 10 January 2013 (UTC)[reply]
Thanks. One follow-up - you used EW chiral coupling as an example that breaks parity symmetry. It's a good example to clarify with. How would one describe parity symmetry accurately as a "law of nature", in the sense of a definition that also makes clear its limits or domain as a law and therefore also makes clear where the potential lies for its non-applicability or overriding in some circumstances?
(Sorry for the cumbersome wording, I'm trying to avoid using the term "law of nature" as it seems parity and EW symmetry are laws of nature only to the extent that one is careful to include in the definition sufficient information to make clear where they are not absolute. Not saying that this detail should be in the article but it could be helpful to have a more rigorous statement of this law of symmetry in mind for editing) FT2 (Talk | email) 14:36, 10 January 2013 (UTC)[reply]
I don't see why you would avoid the term "law of nature". Symmetries are laws of nature in the same way that conservation laws are laws of nature. (In fact, there is a close relation between the two through Noether's theorem.) Broken symmetry laws correspond to conservation laws that might not always hold. For example, conservation of mass holds for chemical processes, but not for nuclear processes. (Note that this is not a good example for this article, because on of the features of spontaneous symmetry breaking is that it breaks the symmetry but not the corresponding conservation law).TR 15:04, 10 January 2013 (UTC)[reply]
I think I did not completely answer your question. Lets be specific in the case of CP symmetry. The CP symmetry states that all equations of motion should be the same if we exchange left and right and the sign of all charges. Essentially, this symmetry exchanges all particles with their anti-particles. As a consequence, the ratio between matter and anti-matter cannot change in any process that obeys CP-symmetry. Violation of CP-symmetry is therefore essential to explain why there is more matter than anti-matter in the universe. CP-symmetry is in fact violated in the standard model by strong interactions involving all three generations. (But not enough to explain the observed asymmetry between matter and anti-matter.TR 15:18, 10 January 2013 (UTC)[reply]
I think I can state the question a little more clearly now. Suppose one is told there is a "law" about conservation of mass, which "almost always" holds but can be violated in nuclear processes. That's about the level of understanding my question is coming from. One would conclude that the reason for the apparent violation is probably not that nature decides laws whimsically, but that the statement "mass is conserved" is an incomplete description (or special case) of some more fundamental law which does not have known exceptions.
A fuller description is that energy is conserved (a law we have found no exceptions to and which seems to be a universal law of nature in the truest sense), and that provided we remember that matter can be converted to and from energy, then 1/ in cases where mass-energy conversion does not occur, mass will be conserved too, and 2/ if we found a situation where mass appeared not to be conserved in some process, we would suspect initially either human error or some covert conversion of mass to/from energy, to find neither of those would be very significant indeed.
Hopefully that is an example that illustrates what I'm asking. (Fundamental laws probably don't have exceptions; to the extent they do they tend to highlight the incompleteness of the statement on what the "law" in question really is.) Mass-energy was a very good one to raise in the context and illustrates it very nicely. FT2 (Talk | email) 00:05, 11 January 2013 (UTC)[reply]
There are many examples in nature of "almost" conservation laws that are not incomplete descriptions of a more fundamental law. Typically, these can be explained by the existence of broken symmetries. For example, in the theory of strong interactions all the quark fields are invariant under phase rotations. Consequently, the number of quarks with a particular flavor (i.e. quantum numbers like strangeness or charmness) are conserved by the dynamics of the strong interaction. However, the interactions of the (much rarer) weak interaction are not invariant under phase rotations of the quark fields, allowing the number of quarks of a certain flavor to change. (allowing the heavier quarks to decay to up and down quarks.)
In this sense the mass-energy example is rather unfortunate.TR 09:51, 11 January 2013 (UTC)[reply]
And that last example was rather helpful. Thanks. Unlikely to get much clearer at this point (and this might be about enough to reassure me a bit on the lay-reader aspect of it - we'll see); it's a good example to have in mind. FT2 (Talk | email) 13:35, 11 January 2013 (UTC)[reply]
(In lay terms what I take away here is that "laws" such as these may be called laws, but they should not be understood as absolutes or absolute conservation laws (in the sense that we believe conservation of energy or speed of light may be). It isn't that they are "laws of nature" in the lay sense of "fundamental and with no known exceptions". Rather they are statements that under certain conditions, or subject to certain boundary criteria or limitations, these symmetries are believed to dependably hold as far as we know at present. This is probably a "given" in the scientific world, but if so, it's an implicit "everyone knows that" of science - it might not be understood as a "given" to that effect in the public community and could lead to confusion. So it's been a valuable conversation, thank you!) FT2 (Talk | email) 13:46, 11 January 2013 (UTC)[reply]

(unindent) I have now edited the wording since I think this gives a better way to say it. The problem you raise about the technical term "broken symmetry" (ie a field may cause a broken symmetry) is its jargon. But the concept can be expressed nicely in terms of broken conditions per above - symmetries hold under certain conditions, and a field exists which 'breaks' those conditions. That's very ordinary English, not jargon. So I've used it as it's both simpler and (per above, I gather?) maybe also a bit more exact. FT2 (Talk | email) 17:49, 16 January 2013 (UTC)[reply]

Ground vs. vacuum state?

In three places we refer to the "vacuum state" and eight places we refer to the "ground state". Are these synonyms, and should we make them consistent?

Also if they are synonyms, then are the articles vacuum state and ground state essentially the same or extremely similar topics?

FT2 (Talk | email) 13:10, 21 January 2013 (UTC)[reply]

They are not synonyms.--85.230.137.182 (talk) 23:24, 2 February 2013 (UTC)[reply]
As the ground state article says: "The ground state of a quantum field theory is usually called the vacuum state or the vacuum"...--85.230.137.182 (talk) 23:45, 2 February 2013 (UTC)[reply]
  1. ^ R. Castmore and C. Sutton, "The Origin of Mass", New Scientist 145, 35–39 (1992). Y. Nambu, "A Matter of Symmetry: Elementary Particles and the Origin of Mass", The Sciences 32 (May/June), 37–43 (1992). J. LaChapelle, "Generating Mass Without the Higgs Particle", Journal of Mathematical Physics 35, pp. 2199–2209 (1994).
  2. ^ Max Jammer, Concepts of Mass in Contemporary Physics and Philosophy (Princeton, NJ: Princeton University Press, 2000) 162
  3. ^ Jammer 163, who provides many references in support of this statement.
  4. ^ M.J.G. Veltman, "The Higgs Boson", Scientific American 255 (November), 88–94 (1986).
  5. ^ Gerard Piel, The Age of Science: What Scientists Learned in the 20th Century (New York: Basic Books, 2001) 160
  6. ^ Tony Rothman, and George Sudarshan, Doubt and Certainty: (Cambridge, MA: Perseus Publishing, 1998) 238, Questia, Web, 13 Jan. 2012.
  7. ^ Piel 180
  8. ^ Mendel Sachs, Relativity in Our Time: From Physics to Human Relations (London: Taylor & Francis, 1993) 155-156
  9. ^ Frank Wilczek, and Betsy Devine, Longing for the Harmonies: Themes and Variations from Modern Physics (New York: W. W. Norton, 1988) 240-246
  10. ^ Top 5 common misconceptions about the Higgs particle, Nov 13 2012, by physicist Mark Kruse, Duke University