Talk:Higgs boson/Archive 4

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Archive 1

Archive 2

Archive 3

Molasses analogy fails

The article says:

"The field can be pictured as a pool of molasses that "sticks" to the otherwise massless fundamental particles that travel through the field, converting them into particles with mass that form (for example) the components of atoms."

This analogy suggests that, like a marble moving through actual molasses, a particle moving through space would slow down and eventually stop. Obviously this is not what Newton's first law says and what we observe. So either the analogy should be removed, modified or the point should be made explicitly that the mollases-like nature of the Higgs field does not slow down moving particles. (I assume that the analogy does not imply that particles do eventually slow down in free space!) A poor analogy like this does not help people. — Preceding unsigned comment added by Informationtheory (talk • contribs) 23:10, 7 July 2012 (UTC)

It is just a general analogy, it doesn't really try to say they are the same thing or have the exact same effect. I have wondered the same myself though... how can a force or field resist acceleration the way the Higgs field does? And is it the only field that does that? I do recall that accelerating charged particles emit photons, so is this similar? CodeCat (talk) 00:00, 8 July 2012 (UTC)

In my opinion it is just a bad analogy, it is not like molasses. 85.230.137.182 (talk) 01:24, 8 July 2012 (UTC)

For inclusion in Wikipedia, it doesn't matter if the analogy is "good" or "bad", but simply whether or not the analogy can be verified to be in use, as reported by reliable sources. If a notable expert says that a widely-used analogy is "bad", then that fact can also be reported here. It looks like that molasses analogy has been tagged as uncited since January, so removal is probably appropriate now since there have been many, many eyes on this page and it has remained uncited. --Ds13 (talk) 01:37, 8 July 2012 (UTC)

Naa, all things that are included should be verifiable but all things that are verifiable should not be included. 85.230.137.182 (talk) 16:59, 10 July 2012 (UTC)

Pages 230 and 231 of Jim Baggott's (excellent BTW) "Quantum Story" has a different analogy for the Higgs field based on a cocktail party, a celebrity, and rumors of a celebrity. Not sure it's any more helpful than molasses. Woz2 (talk) 12:51, 8 July 2012 (UTC)

I went ahead and swapped the out the molasses analogy in favor of the cocktail party one. It's a better analogy IMHO, and the history of where it came from is pretty fascinating. Csmallw (talk) 02:41, 11 July 2012 (UTC)

A particle behaving like Higgs

This is just a layman's question, but what is the difference between a new particle behaving like Higgs boson and, um, just a Higgs boson? If an animal is behaving like a duck, isn't it just a duck? It would be nice if someone knowledgable can clarify what still need to be verified. -- Taku (talk) 13:09, 8 July 2012 (UTC)

The article says "whose behaviour so far was consistent with a Higgs boson". I think you missed out the words in bold. So far the new particle acts like we'd expect a Higgs to act, but when it's tested at greater length (now we actually know it's confirmed to exist) it might or might not ultimately prove to be one. In simple terms it's had a number of properties verified, but not enough to confirm it is a Higgs boson.

That said I agree it would be nice to summarize what exactly is known about this particle, and what isn't. FT2 ^{(Talk | email)} 13:35, 8 July 2012 (UTC)

By the way The Economist leader flat out says that the Higgs has been found http://www.economist.com/node/21558254 Either they have inside info we don't, or they are being sloppy. Woz2 (talk) 15:30, 8 July 2012 (UTC)

Very sloppy. This is plainly not true, "On July 4th physicists working in Geneva at CERN, the world’s biggest particle-physics laboratory, announced that they had found the Higgs boson." --NeilN ^{talk to me} 16:05, 8 July 2012 (UTC)

Yes. It also says "Without the Higgs there would be no mass." which seems to gloss over the fact that the proper mass of a composite particle can be finite even if the proper masses of its constituents are all zero (e.g. a glueball) But I digress... Woz2 (talk) 18:38, 8 July 2012 (UTC)

Guys pleases take from this source http://www.britannica.com/EBchecked/topic/265088/Higgs-particle and it would help you a lot.--♥ Kkm010 ♥ ^{♪ Talk ♪} ߷ _{♀ Contribs ♀} 11:01, 9 July 2012 (UTC)

Thanks for the pointer. But I'm concerned about WP:COPYVIO if we "take" from it. Thoughts? Woz2 (talk) 12:22, 9 July 2012 (UTC)

It's not a copyright violation if you write your own text based on the information in the article. Only the text is copyrighted, the information is free to be used. CodeCat (talk) 12:46, 9 July 2012 (UTC)

That Britannica article actually contains quite a few errors/inaccuracies. (For example, the Higgs mechanism does not endow all elementary particle with mass. There are massless particles. Also at this point it is unclear how neutrinos get their mass, the Higgs mechanism may or may not be involved.) Nor does it seem vary accurate to refer to gauge bosons as subatomic particles.T R 21:31, 9 July 2012 (UTC)

In addition there are hypothetical particles with proper mass that definitely do not get their mass from the HM (assuming they exist, that is). glueballs Woz2 (talk) 22:41, 9 July 2012 (UTC)

But in defense of Britannica, those are not really elementary.T R 06:13, 10 July 2012 (UTC)

Well, subatomic particle typically just means ‘particles smaller than atoms’, not necessarily ‘particles found in atoms’: for example strange baryons are often referred as such. (And there are (virtual) photons in atoms and (virtual) gluons in nuclei, to the extent that this statement makes sense – I know I'm using perturbative language in a non-perturbative context, but if you want to be that rigorous there actually aren't electrons in atoms either.) A. di M. (talk) 09:49, 10 July 2012 (UTC)

Sorry for intruding but I just want to answer the question. The main reason the boson discovered is a Higgs Candidate is due to its decay channels being consistent with how the Higgs Boson should operate. For example, the 2 gamma ray photons could only come from a particle interacting with a massive charged particle in a 1-loop Feynman Diagram, In this case the Higgs interaction with a virtual W-Boson or Top-Quark Loop. The Higgs is neutral so the only way it could release 2 photons via an electromagnetic interaction is if it coupled to a charged, massive particle via the Higgs Mechanism itself. The Higgs couples to the most massive particles in the Standard Model, The Top Quark and the W and Z bosons. Since the W-Boson and Top Quark are charged photons are released, Since the Z-Boson is neutral it just decays into 2 Leptons. Since these channels were observed at ~5 femtobarns it is a Higgs Candidate. No Tau-Tau Channels were observed so it is probably not a ZZ or WW Boson. Also this boson fits into the expected production regieme from the LHC, namely Gluon-Gluon fusion. Why it is a low-mass Higgs is a job for theorists but it could be a singlet Higgs in the expected triplet that may be discovered when the LHC is up to full power in 2015 or it could be a Supersymmetric Higgs. In that case observation of the Higgs-> gamma-gamma cross section will yield the answer, we may have to wait untill 2015 though. MuonRay (talk) 19:36, 9 July 2012 (UTC) — Preceding unsigned comment added by MuonRay (talk • contribs) 19:30, 9 July 2012 (UTC)

I just have to ask-- is there any chance of a ZZ boson interacting with Top quark? I mean a sort of ZZ Top interaction? Just to make Texas weep for not having the SCSC sited there? S B H arris 20:13, 10 July 2012 (UTC)

Yeah, there could be a term in the La Grangian for that. A. di M. (talk) 14:37, 11 July 2012 (UTC)

Higgs-thingy

I stand by my comment - we do not need to describe the characteristics of the Higgs field in the introduction to the Higgs boson as this is detail on the field not the boson. It's useful to explain up front (1) SM solves the mass problem by positing a field such that particles interact with it and gain mass by doing so. (2) We can't directly detect this field but we can prove it exists and measure its properties indirectly by instead investigating whether its quantum particle exists. (3) This thereby shows whether SM is basically correct or not in this last area, which (4) is why the search matters. FT2 ^{(Talk | email)} 21:24, 11 July 2012 (UTC)

I disagree that it's circular logic. This is not an article demonstrating the existence of the Higgs boson, it's an entry describing "what it is" as a concept (as of today). There is no "assuming what's been set out to prove" issue, as it has already been assumed as a concept important enough to have a WP entry. It is then perfectly natural that this entry describes what its properties are "if it existed". Therefore, yes, detecting any mass means to measure the Higgs field, assuming it existed in the first place. This is what makes it different from "any" boson. But, would you not be detecting Technicolor? Yes, according to "that" concept. Which is not discussed in this entry. Gibbzmann (talk) 13:49, 12 July 2012 (UTC)

Some of this agreed, some not. This is an article describing the Higgs boson, and the introduction is intended to summarize key points for readers. We do need to say it is the quantum of the field. We don't need to then explain the details of the Higgs field in the introduction to do that, any more than we explain details of the electromagnetic field in the introduction to electron. In fact the introduction to that article doesn't describe the characteristics of the EM field at all. Nor should we describe the characteristics of the Higgs field in the lede either. We just need to say it is a field that's believed to give rise to mass in some particles, and if correct, can be detected by detecting its boson. Everything else about the Higgs field belongs in the body or in the Higgs field article, and out of the lede. That is the point. FT2 ^{(Talk | email)} 14:29, 12 July 2012 (UTC)

You got the wrong particle there; I think you are looking for photon rather than electron. Martijn Hoekstra (talk) 14:52, 12 July 2012 (UTC)

That's right, it is indeed the photon the particle you should have been looking at. And the photon is special in that it mediates the EM field, and this is stated in the lead of that article about the photon even though the EM radiation and EM force have articles of their own. The 'Higgs boson' is an article about the boson and not the field, that's right, but it is not an article about 'any' boson. As such, you ought to say what is special of THIS boson, and therefore of its field, and yes, even in the lead. Regardless, my previous comment targeted the presumpption that to include it in the lead would be to assume what is not demonstrated; which is not the case, because it is the very article that presumes the hypothetical existence of the Higgs boson (whcih indeed already exists for sure as a concept, or as a model, whatever). Gibbzmann (talk) 16:33, 12 July 2012 (UTC)

What seems clear to me is that, right now, '(intro to) Higgs Field', 'Higgs Boson' and 'Higgs Mechanism' are three increasingly technical takes on the same subject matter. If the announcement heat has died down a bit, then before we start hacking into leads here and there for the sake of article purity, maybe we should have a plan for organizing all this higg-business. Darryl from Mars (talk) 15:20, 12 July 2012 (UTC)

What happens if they split it?

I mean, if it created the universe, then wouldn't splitting it theoretically blow up the universe? Seriously? I'm kind of worried. --86.141.99.56 (talk) 23:15, 10 July 2012 (UTC)

Not particularly...especially since it's the field that gives things mass, the boson itself is just a slight ripple in the field. Darryl from Mars (talk) 23:36, 10 July 2012 (UTC)

Atoms can be split because they are made out of smaller particles (protons and neutrons). But there is nothing so far that indicates any of the force carrying bosons, including presumably the Higgs boson once we find it, are made up of smaller particles. So the idea of 'splitting' it is meaningless, there's nothing to split it into. Also, it is not physically possible for something as small as a Higgs boson to blow up the universe. What gives atomic bombs their power is the fact that splitting the atoms inside the bomb fuel releases huge amounts of energy, because the smaller atoms that result are more stable and energetically 'happy' than the big uranium atoms they formed from. And when a lot of energy is lost, this is equivalent to a smaller amount of mass (0.1% of the total mass of each uranium atom split) according to Einstein's formula E=mc². Applying that same principle to the Higgs boson, for it to have enough energy contained within it to blow up the universe, it would need to have as much mass as a few galaxies. Which obviously isn't the case! CodeCat (talk) 00:42, 11 July 2012 (UTC)

That can't happen with the SM Higgs field, but see False vacuum. A. di M. (talk) 01:04, 11 July 2012 (UTC)

Don't worry. The Higgs splits itself in something like 10^-26 seconds producing, typically, two bottom quarks, which themselves decay into mostly pions, which smack harmlessly into the detector. If the Higgs field itself collapsed, we'd be in trouble. However, any civilization with the power to do that has technology so godlike that it wouldn't be a problem. Law of Entropy (talk) 06:54, 11 July 2012 (UTC)

CERN did a detailed red-team blue-team study on this. See also Ultra-high-energy cosmic ray The earth has been bombarded with much higher energy collisions for billions of years, and the effects are only noticable in very sensitive experiments. You can also check here ;-) http://hasthelargehadroncolliderdestroyedtheworldyet.com/ Drive safely! Woz2 (talk) 11:03, 11 July 2012 (UTC)

Thanks. Just checking. --86.141.99.56 (talk) 16:41, 11 July 2012 (UTC)

You are welcome. Please continue to worry about pandemics from either a) human/chicken/pig co-habitation or b) accidental pathogen release from a biolab in a world with rapid, high-volume, global passenger air travel (see 12 Monkeys), and also weapons of mass destruction... but I digress. Woz2 (talk) 23:08, 11 July 2012 (UTC)

There. A. di M. (talk) 00:32, 12 July 2012 (UTC)

I vociferously object to section 8.2 "The Fermi Paradox." Why is there no "Bose Paradox" also? Fermi is well known to be "the physicist with the most stuff named after him." It shows a clear bias. :-) Woz2 (talk) 01:49, 12 July 2012 (UTC)

Well, if you count some 18th- and 19th-century mathematical physicists as physicists rather than (or as well as) mathematicians, I doubt that's the case. A. di M. (talk) 10:20, 12 July 2012 (UTC)

Good point... but until just now Fermi level and Fermi surface were missing from Fermi (disambiguation)... Must be more out there... I've started List of things named after Enrico Fermi and have got my google-fu on to win the bet... Majorana fermion will not be added to the list. ;-) Woz2 (talk) 13:31, 12 July 2012 (UTC)

OK I think Gauss wins on number, but Fermi wins on variety (element, class of particles, one with name spelt backwards (imref),...) Cheers! Woz2 (talk) 16:35, 12 July 2012 (UTC)

Tevatron and LEP

If the new boson only has a mass of 125-127 GeV why did not the Tevatron or LEP find it? 85.230.137.182 (talk) 13:21, 12 July 2012 (UTC)

LEP was able to exclude a Higgs with masses up to about 115 GeV, so that was bad luck. The last analysis of Tevatron data did show a 2.9 sigma excess at 126 GeV, so it's just that they would have needed more statistics. — Preceding unsigned comment added by A. di M. (talk • contribs) 14:07, 12 July 2012 (UTC)

LEP wasn't powerful enough. Although the Tevatron was powerful enough the problem was that 125GeV Higgs decays mostly into b anti-b pairs which produce a large hadronic shower so hard to distinguish. If the Higgs had a higher mass then it would primally decay via a W W pair which is a lot easier to "see". So the Tevatron was able to rule out this higher mass range. This leaves the question why the LHC saw a signal and the Tevatron didn't. The reason is that although it is hard to see b anti-b pairs at low energy the Higgs also decay into two photons which is a lot cleaner signal to see however the Higgs only decays ~0.001 times for every b anti-b decay. So it's a matter of statistics.Dja1979 (talk) 16:30, 12 July 2012 (UTC)

Kaluza-Klein theory

Could the just-discovered Higgs Boson and the radion of Kaluza-Klein theory possibly be one and the same? Or is it possible that they mix and what was observed at LHC was a superposition of the two? 70.99.104.234 (talk) 19:49, 12 July 2012 (UTC)

"unseen field permeates all of space"

The lede of the article contains the statement that the Higgs field is a "unseen field (that) permeates all of space". I know that phrases like this are extremely common in popular media descriptions of the Higgs field. However, that does not reduce the fact that this statement is completely vacuous. All (almost) fields are unseen and permeate all space. As such, the statement is misleading to readers (that don't know what a field is) since it suggests that it differentiates the Higgs from other fields.

The real information that this statement in the media is trying to convey is that the Higgs field (in its ground state) has a non-zero strength everywhere. I propose that we find a formulation that is both more accurate and more informative to a general audience.T R 06:01, 10 July 2012 (UTC)

Actually, in terms of the general reader, most fields are very finite in spatial dimension and filled with grass or AstroTurf. Darryl from Mars (talk) 06:34, 10 July 2012 (UTC)

I wouldn't say that a particular field ‘permeates’ a particular region of space if it vanishes there. But yeah, permeate is not a rigorous term anyway, so we'd better not use it. “... with a non-zero strength everywhere, even in otherwise empty space”? A. di M. (talk) 09:41, 10 July 2012 (UTC)

It has the huge advantage that it's accurate and comprehensible to a lay-reader, while not misleading a technical reader. In a subject this complex and a possible solution that speculatively proposes the existence of a new and undetected field, a little slippage in the introduction and a nod to the non-physicist may be useful. A technical reader is unlikely to be misled. FT2 ^{(Talk | email)} 16:26, 10 July 2012 (UTC)

I like AdiM's suggestion. It accurately covers what is meant in a way that should be accessible to most readers. (much more than the vague "permeates all of spaces").T R 20:33, 10 July 2012 (UTC)

Also A strong smell of turpentine prevails throughout.[1] It's interesting that Guth's "spectacular insight" in 1979 had the false vacuum Higgs field collapse responsible for cosmic inflation, and I think that this was part of Lederer's inspiration for calling it the God Particle. But we know now that the Higgs boson is not the inflaton. I think we really need an insufflationon, as some physicists are definitely blowing smoke you-know-where. My own suggestions for a really tough fundamental particle (hardon and futon) have been rejected. Like they rejected my idea for Wonderful and Marvelous for the last two quarks, which I thought would be handy in case supersymmetry turned out to be true. Drat. S B H arris 02:36, 11 July 2012 (UTC)

The force is strong with this one... — The Hand That Feeds You:^Bite 20:18, 10 July 2012 (UTC)

But the Higgs has no colour charge! A. di M. (talk) 01:10, 11 July 2012 (UTC)

I hate to point this out, but the Swonderful and the Smarvelous would both be bosons... so brace yourselves for a wave of nationalist cheerleading for the credit when they are discovered... ;-) Woz2 (talk) 02:13, 12 July 2012 (UTC)

I'm really unhappy with the second of these sentences in the introduction:

The existence of the Higgs boson and the associated Higgs field would be the simplest of several methods to explain why some other elementary particles have mass. According to this theory, certain other elementary particles obtain mass by interacting with the Higgs field which has non-zero strength everywhere, even in otherwise empty space.

The problem is the 2nd sentence is poorly targeted. It introduces the "Higgs field" with no context, then says other particles hypothetically interact with this "Higgs field"... but what is this Higgs field? Basic context is absent. Readers don't necessarily need to know the field is "non-zero everywhere even in otherwise empty space". This doesn't help understand the Higgs boson or the search. Technical readers probably don't need details of the Higgs field in the introduction of this page either.

For the purposes of the Higgs boson introduction, this part of the intro needs to say two things: (1) According to SM a field exists everywhere [like many other fields] that we can't directly detect, and some particles obtain mass when they interact with it, (2) Although we can't directly detect that field, we can detect its related quantum which would prove whether or not the field exists and its properties.

FT2 ^{(Talk | email)} 13:55, 11 July 2012 (UTC)

I strongly disagree. The fact that the Higgs field has a non-zero strength everywhere is the central property of the Higgs field that makes the mechanism work. It is this property that others are trying to get at when they say that the field "permeates all of space". Without this property, it is impossible to understand why interacting with this field would give particles mass all the time and everywhere.

Note that the Higgs fields is not "unseen". We are continuously detecting the Higgs field. Every time we see an electron with mass, we are detecting the Higgs field! (Similar to the way you detect an electrical field through its effect on observed charges.) This makes saying that the Higgs field is "unseen" untrue. The reason we need to detect the quantum of the field, is because a lack of the quantum would falsify the hypothesis that we are seeing the (effects of) the Higgs field through the observation of mass.T R 19:03, 11 July 2012 (UTC)

Non-zero-strength is a central property of the field not the boson. In an introduction to the boson the field's properties are not pivotal. The non-zero-everywhere-ness of the Higgs field doesn't need to be in the lede to understand the concept of the boson and putting it there doesn't enhance understanding of the boson.FT2 ^{(Talk | email)} 21:24, 11 July 2012 (UTC)

The non-zero-strength of the field is central to understanding why the Higgs field gives mass, and therefore to understanding why the Higgs boson is important. (And also why the Higgs boson is rare, even though we see particles with mass all around us).T R 04:56, 12 July 2012 (UTC)

No. The non-zero-ness central to understanding how the field works, and the field is central to understanding mass and therefore why the boson matters. But the non-zero-ness is not central to understanding the boson. A is central to B, and B is central to C does not imply A is central to C. It's important in the body of the article; not in the intro. FT2 ^{(Talk | email)} 08:03, 12 July 2012 (UTC)

I carefully stated: "According to SM a field exists everywhere [like many other fields] that we can't directly detect". Do you have a device to directly detect the Higgs field, or know of a theoretical way to build one? I doubt it. An electron isn't one, and we are not "continually detecting the Higgs field" by observing electrons. That's circular logic - proposing a Higgs field as one way (of several) to explain why electrons have mass, then arguing that seeing an "electron with mass" proves the field exists. The same logic would prove Technicolor, braid, or magical pixies as the reason.FT2 ^{(Talk | email)} 21:24, 11 July 2012 (UTC)

An electron in a mass spectrometer would be a rather direct way of measuring the Higgs field strength. I could probably build one from an old CRT (although it would not be very accurate). This logic is not any more circular, than say that you detect the Earth's gravitational field by seeing an apple fall from a tree. Of course, such a measurement presumes that the field exists in the first place. "Proving" that requires the hypothesis to withstand further attempts at falsification. (such as detecting the excitations of the field).T R 04:56, 12 July 2012 (UTC)

You're presuming the very thing you set out to prove.

Once the Higgs mechanism is agreed to be produced by a Higgs field, and that Higgs field's free parameters are characterized so that we can directly know its strength from other measurements, then we can perhaps deduce its strength in various ways. But the baseline here is that the means of production is itself the point in question (sounds communist!) so showing that mass exists or any specific mass, is not proof of a specific generating method. At this point it's extremely circular.
Right now, the field itself isn't directly detectable. We instead have to detect its quanta. The position we're in is that we speculate an "electric field" exists, so we seek to prove it by seeing if we can create and prove the existence of "electrons" which theory says must exist if the field does, rather than directly detecting the effect of an electric field. Right now could we in principle measure the Higgs field itself at a point moment by moment by its effect on other particles, similar to the way we could measure variations in gravity or electric potential in or around a circuit? I think not.

FT2 ^{(Talk | email)} 08:03, 12 July 2012 (UTC)

Right now could we in principle measure the Higgs field itself at a point moment by moment by its effect on other particles, similar to the way we could measure variations in gravity or electric potential in or around a circuit? I think not. Then you think wrong. It is very simple to measure variations in the electron mass at a point over time, and therefore variations in the field strength of the Higgs (A simple oscilloscope will do the trick,) Of course, this is not a very useful experiment in trying to prove that the field actually exists, but it show that it is incredibly simple to measure the Higgs'field strength. (Note also that it is impossible to deduce the Higgs field strength from measuring the Higgs boson!)

Note that in your analogy with the electric field, it would be the photon that needed to be detected. However, we knew about the electric field long before we knew about photons (or EM waves for that matter).

Also note that this exactly the point that is confusing to many lay readers. "How come that a field that has such a huge effect everywhere, is undetectable?" The answer is, people saying that the field is undetectable are simply mistaken. (And confusing the lay reader in the process).T R 16:34, 12 July 2012 (UTC)

Well, the mass of the electron is the value of the Higgs field times the Yukawa coupling between the Higgs field and the electron, so a measurement of the electron mass doesn't count as a measurement of the Higgs field unless you know the Yukawa coupling somehow else. A. di M. (talk) 09:35, 13 July 2012 (UTC)

But we do know the Yukawa coupling of the electron to the Higgs field, so the point is moot. Put even if you didn't, measuring the electron mass is a simple method of measuring hypothetical variations in the Higgs field in relative units. (Of course, in practice the Higgs field does not vary, in time or space, except for the very tiny variations caused be a rare Higgs boson event.) Point still stands, it is misleading to say that you cannot detect the Higgs field. (the detection is just rather boring because you are only going to see the rather featureless).T R 18:40, 13 July 2012 (UTC)

What? I thought the Yukawa coupling was measured by measuring the electron mass and dividing it by the Higgs vacuum expectation value (as computed from the Fermi coupling constant). Is there another way to measure it? (Anyway, we could say “directly detect” – yeah, if you take that too narrowly the only particles you can “directly” detect are the photons entering your eyes, the air molecules hitting your eardrum etc., but some indirect detections are more indirect than others.) A. di M. (talk) 23:02, 13 July 2012 (UTC)

Yes, you have to measure the electron mass to get the Yukawa coupling, but you only have to do that once to "calibrate" your Higgs field measuring device. After that you device is set to measure the Higgs field at other locations and times. (With the boring result of measuring the same value over and over again because the Higgs field is in its groundstate.)T R 22:11, 14 July 2012 (UTC)

Is "all of space" supposed to include/inply the center of the earth as well?165.212.189.187 (talk) 15:35, 12 July 2012 (UTC)

Interesting question...I would assume so, yes. Darryl from Mars (talk) 15:40, 12 July 2012 (UTC)

“Interesting”? Why, what's so special about the centre of the Earth? A. di M. (talk) 16:13, 12 July 2012 (UTC)

Not interesting as in 'interesting, I hadn't thought of that', interesting as in '...I bet you have a very interesting reason for asking that'. Darryl from Mars (talk) 16:22, 12 July 2012 (UTC)

Try this: If you're so concerned with the "lay person's" understanding in the lede then most lay people (or just me) think all of space is "out there" and doesn't include objects like the planet earth.165.212.189.187 (talk) 17:04, 12 July 2012 (UTC)

Good point. I was assuming that saying “even in otherwise empty space” (emphasis added) implies we're not talking only about otherwise empty space. How would you make that clearer? A. di M. (talk) 09:30, 13 July 2012 (UTC)

"in empty space and massive objects alike". Also does all of space include within black holes?165.212.189.187 (talk) 12:53, 13 July 2012 (UTC)

Presumably yes, as black holes probably have inertia like any other massive object. CodeCat (talk) 12:58, 13 July 2012 (UTC)

or "permeates everything from empty space to black holes"165.212.189.187 (talk) 13:15, 13 July 2012 (UTC)

We know that either quantum field theory as we know it or general relativity as we know it (or both) break down in black holes, so I'd rather not use them as examples, until we have a decent theory of quantum gravity telling us what's going on in there. A. di M. (talk) 17:29, 13 July 2012 (UTC)

On the true nature of 'fundamental-particles', and the Ultimately Real Entity.

All the fundamental-particles, starting from the quarks to Higg's boson, are currently believed by majority of scientists as 'real-things'. But, the fact that many fundamental-particles are very short-lived, decaying into different particles; and the fact that a particle, say an electron, and an anti-particle, say a positron, getting annihilated, leaving behind a pair of photons, imply that all elementary particles are 'process' or a 'phenomenon' of fluctuations generated in some still more fundamental real entity. Higg's field is believed to be present everywhere in the universe; it means that scientists have moved a step closer to religions, according to whom GOD is omni-present, all-pervading and eternal. Hasmukh K. Tank.122.102.125.40 (talk) 10:43, 12 July 2012 (UTC)

It's interesting how much of this comment is actually totally reasonable. It gets a little mystical at the end but...perhaps they should have been talking about the God Field, eh? Darryl from Mars (talk) 10:57, 12 July 2012 (UTC)

With one massive logical failure. "Higg's field is believed to be present everywhere in the universe; it means that scientists have moved a step closer to ____" Fill in the blank. That's the lapse. Science has believed for ages that there may be "somethings" that exist in all places. Look at other fields and structures. To select "god" from all of those possible "exists in all places" candidates, and then to populate god with your own personal concept of that term, along with whatever beliefs your own religion has about "god" such as good or bad, judgment, bible, vedas, quoran, etc... that is the lapse. Stating that "science agrees there are some things that exist in all places" is nothing like saying "science has moved closer to god". Science has had that understanding, or been open to that understanding, for centuries, and philosophers for millennia. FT2 ^{(Talk | email)} 11:53, 12 July 2012 (UTC)

O.K., Let us not give any specific name to 'that which exists everywhere'. The other point is: that elementary-particles may not be the 'things' or 'real-entities'; they seem to be just 'patterns' of 'fluctuations' or 'vibrations' generated in 'that which exists everywhere'. Hasmukh K. Tank — Preceding unsigned comment added by 122.102.125.40 (talk) 12:18, 12 July 2012 (UTC)

Physicists tend to assume the laws of nature are the same everywhere, i.e. they 'exist everywhere'. I do not think that idea is something particularly new in science. Religious people tend to pick the facts that agree with their world-view but ignore those that disagree.85.230.137.182 (talk) 13:31, 12 July 2012 (UTC)

All very interesting, but let us please remember this talk page is NOT for discussions about the topic in general, it is for discussions of specific changes to the article. This is not a discussion forum, regardless of how interesting and civil the discussion.204.65.34.34 (talk) 14:50, 12 July 2012 (UTC)

What, this isn't Facebook? :-) I think we should point 122.102.125.40 over to Pantheism Cheers! Woz2 (talk) 16:53, 12 July 2012 (UTC)

See also Holomovement, Implicate order, and David Bohm's description of the implicate order: "[…] what we call empty space contains an immense background of energy and […] matter as we know it is a small quantized wavelike excitation on top of this background, rather like a tiny ripple on a vast sea". Whether there's a link between the implicate order and the Higgs boson or not, beyond the similarity of words and ideas, I wouldn't yet know. --Chris Howard (talk) 19:04, 12 July 2012 (UTC)

As for stuff that's everywhere... A. di M. (talk) 09:38, 13 July 2012 (UTC)

And one more that's even more basic Field (physics): "In physics, a field is a physical quantity associated with each point of spacetime." Woz2 (talk) 11:28, 13 July 2012 (UTC)

Mathematically yeah; but when normal people talk about there being a (say) magnetic field in some region of space, they normally mean that there's a non-zero (or even a non-negligible) magnetic field there. A. di M. (talk) 12:24, 13 July 2012 (UTC)

Is the "overview" section redundant?

The Overview section currently essentially duplicates the content of the lede. This seems rather redundant, especially since it is also followed by a "general description" section. Should we just get rid of it?T R 10:37, 15 July 2012 (UTC)

I was about to propose the same. I'll remove it now and see if anybody objects. Ptrslv72 (talk) 12:20, 15 July 2012 (UTC)

(a bit late maybe) No objection, I think we're working out how to explain the Higgs to lay-people finally, but the section did have some useful wordings and explanations, rather than just delete I'd like to see them folded into the rest or merged, so we get the best of all that is in it. Was going to, but a long "to do" list here. FT2 ^{(Talk | email)} 20:41, 15 July 2012 (UTC)

Question

"On 4 July 2012, the two main experiments at the LHC (ATLAS and CMS) both reported independently the confirmed existence of a previously unknown particle with a mass of about 125 GeV/c2 (about 133 proton masses, on the order of 10−25 kg), which is "consistent with the Higgs boson" and widely believed to be the Higgs boson. They cautioned that further work would be needed to confirm that it is indeed the Higgs boson (meaning that it has the theoretically predicted properties of the Higgs boson and is not some other previously unknown particle) and, if so, to determine which version of the Standard Model it best supports."

Would you kindly explain what exactly was observed? How do you know this is unknown particle? What if it was not Boson, but rather compendium of 133 protons stuck together?

70.53.225.161 (talk) 22:09, 7 July 2012 (UTC)

It has to do with probability, they look at a very large number of events and compare them to how probable a certain outcome should be if a higgs boson exist and if it does not. Imagine you wanted to see if a dice was somehow manipulated so side 6 would turn up more often. Let us say you can not inspect the dice directly, only see the outcome of each throw. Can you determine if the dice is unfair or if someone is simply lucky and get lots of sixes? If you get to see the outcome of many throws, you could record them. After many throws, if the dice is fair all sides should come up about the same amount of times, if it is unfair the side six should come up more than the others. When looking for the higgs boson, they know how often a "compendium of 133 protons" (or any other known combination) should turn up and have concluded that the outcome of the many recorded events does not match what they would have expected if there was no higgs boson at ~125.5 GeV. So there is most likely an unknown particle with that mass. Now they are going to try and figure out what the properties of this new particle is to see if it matches the standard model higgs boson or not. 85.230.137.182 (talk) 01:22, 8 July 2012 (UTC)

They found an excess of 2 photons at about ~125.5GeV. Excesses are caused by resonances when particles decay (133 protons would not decay into 2 photons as charge conservation and spin conservation prevents this). As it's 2 photon means that it's spin 0,2,4 so it is a boson. If it is the Higgs boson then it will be spin 0. Again the 2 photon tell us that it is neutral which the Standard Model Higgs is predicted to be. Obviously this is early days, so not all the information about this particle, that has been discovered, is in.Dja1979 (talk) 01:50, 8 July 2012 (UTC)

You didn't answer my main question: what exactly was observed? What kind of experiment was made? What was recorded and how?70.53.225.161 (talk) 13:59, 8 July 2012 (UTC)

Go read Large Hadron Collider, ATLAS experiment and Compact Muon Solenoid. A. di M. (talk) 15:10, 8 July 2012 (UTC)

I thought I did answer your question 70.53.225.161, They observed more 2 photons with an energy of 125.5GeV than they expected from noise. For the type of experiment and how it was recorded It's best if you read up on the experiments as it's complicated, but briefly they smash the protons together (actually quarks but that's off point) this creates a lot of energy. The energy then forms particles one of which is a Higgs. This Higgs then decays through various channels one of which is the two photon channel. The CMS and ATLAS detector are made up of various detecting material one of which is Electromagnetic calorimeters. It is in these calorimeters that the photons deposit their energy all 125.5GeV of it. The data is then compressed and stored and various selection cuts are made to the data by the analysis groups and the 125.5 GeV photons position and track are reconstructed so that it is seen that they have 125.5GeV of energy and they come from a point source. See my previous answer on why they know it isn't 133 protons stuck together and why it's a boson and what its mass is. We still, however, don't know it is a Higgs Boson.Dja1979 (talk) 19:08, 8 July 2012 (UTC)

So if I summarize it shortly, they didn't observe any particle named Higgs Boson, but rather 2 Photons which in certain apparatus registered a number which corresponds to Higgs Boson. Are they implying that these 2 photons were omitted by Higgs Boson? What is the reason for such implication? Any particle can omit photons.

70.53.225.161 (talk) 13:57, 9 July 2012 (UTC)

This isn't actually the place to ask such questions, as interesting as it is. This talk page is for discussing improvements/changes to the present article. For general questions like this please use the science reference desk. Polyamorph (talk) 14:24, 9 July 2012 (UTC)

Quick answer anyhow (and agree, this isn't the page for such discussion) - indeed "any particle can emit photons". But in this case it's more like "very few particles will decay according to very specific decay routes, emitting very specific numbers of photons of very specific energies, and (in a number of decay paths) other particles again of very specific momentum, energy, spin, and the like. The LHC detectors capture a huge amount of data about each of the trillions of collision outcomes (ie what particles/photons are emitted, what properties they have, and what happens to them), and these have to follow a large number of well-established laws regarding conservation, and probabilities of various decays. So for example it might be possible to say (example only) something like this:

"X million proton-proton collisions occurred. N% should result in a Higgs boson creation if the Higgs boson has mass M. Of these Higgs bosons, 17.3% should decay this way, 42.6% that way, 29.44% a third way, and the rest in a fourth way. For each of these decay routes we know what particles and photons should be expected to reach our detectors, what energies they should be expected to have, what properties should be detected as they pass through, what proportion of them should further decay which ways....."

In other words, there is a lot of "If the Higgs boson existed as the Standard Model suggests, then we have a very good idea what we should see". Conversely given what we're seeing, the math can be worked backwards to say what the probability is that what we're seeing shows evidence of a Higgs boson of mass M. Repeat 300,000,000,000,000 times, then find multiple completely separate experiments, with completely different methods and detectors, and completely different teams, reached the same conclusion without conferring..... it gets you a very high level of certainty. FT2 ^{(Talk | email)} 17:58, 11 July 2012 (UTC)

If person reading my question is competent to respond, I see no reason why this place can not used for my question. After all, responses to my question would help to improve the contents of the article because those questions should be addressed in the article.

From the responses, I may infer only that the latest experiments did not produce data which would contradict existence of Higgs Boson. It is my understanding also that previous experiment did not produce any contradicting results either. So, what is the big deal then?

The big deal would start when you can produce this particle at will at the quantities you desire and make experiments to investigate its properties.70.53.225.161 (talk) 13:42, 17 July 2012 (UTC)

You've got it backwards, in a couple ways. data contradicting it isn't strictly possible, just not finding it. And the properties of the particle were, for the most part, understood beforehand; it's the fact that the thing they found (as there is undeniably [or, to five sigma] a 'thing' found) has the properties which they expected the Higgs Boson to have that makes them confident. Of course, I'm not arguing you have to be excited about this; if you really must have a big deal, I suggest Subway's $5 Footlong. Darryl from Mars (talk) 13:53, 17 July 2012 (UTC)

They have been colliding protons at very high energies. When the particles collide they recombine into new particles, for example two photons, according to certain rules (such as the total amount of energy needs to be the same, just like momentum, charge and spin, etc). If the higgs boson exist a collision could result in one being created, but it would immediately decay into more stable particles (like the two photons), therefore it is not possible to directly detect the higgs boson, instead they look at familiar particles like photons, etc. The problem was they did not know what mass (energy) the higgs boson would have, more than that it should exist within a certain mass/energy range so they had to look for anything out of the ordinary within that range. They knew approximately how many of each group of particles should be produced (how probable each type of decay) if there was no higgs boson, so they have been comparing the results with what to expect if the higgs boson did not exists. What they finally have found is that there is too many particles than expected in the 126 GeV area (like the excess of photon pairs) than there would be if there was no boson in that range, with 99.9999% certainty, so the conclusion is that they have found a new boson with a mass of ~126 GeV. The best known explanation is that it is the higgs boson. Indeed, it is even more interesting to find out what other properties this new particle has and if they are the same as predicted by theory, that is what they are going to do next but it requires even more data and will take many years. The discovery was exciting because up until now there have been a very real possibility the higgs boson did not exist at all, now it seems like there is strong reason to believe it does. In the end a theory is only a theory if it can not be verified by experiments, most theories turn out to be wrong. 85.230.137.182 (talk) 20:54, 17 July 2012 (UTC)

Higgs confusion redux

There's way too much confusion between the Higgs mechanism (considered confirmed but origins unknown) and the Higgs field (speculative, leading explanation of several, tentatively proven by demonstrating the existence of its quantum).

There's also confusion (fueled by media) over the role of the field and the boson, whose actual significance seems to be - (a) proves the field and hence the origins of the mechanism, (b) thus proves core standard model or discriminates between valid and invalid models, and (c) once we know more about the field/mechanism there's considerable potential for "new physics" in theory and experiment which can't be accessed until this area is clearer.

It also seems to be more correct that it's the field that gives mass to some particles rather than the boson (still often misunderstood), and the more profound significance of the boson at present is because it a window onto the field and mechanism, and to validate, test or obtain relevant data for these areas of SM and other advanced theories.

I've edited the intro to try and put this in a logical order that makes these a bit clearer:

The Higgs boson or Higgs particle is a proposed elementary particle in the Standard Model of particle physics. The Higgs boson's existence would have profound importance in particle physics because it would prove the existence of the hypothetical Higgs field - the simplest and most favoured of several proposed ways to explain the origin of the symmetry breaking mechanism known to cause some particles to have mass. Confirmation of the answer to this question is likely to greatly affect human understanding of the universe, indicate which of several current particle physics theories are more likely correct, and open up "new" physics beyond current theories. The leading explanation is that these particles acquire mass by interacting with a Higgs field, which has non-zero strength everywhere, even in otherwise empty space. If this theory is true, a matching boson—the smallest possible excitation of the Higgs field—should also exist and be detectable, providing a crucial test of the theory.

Advantages -

Acknowledges the importance of HB but immediately says why - because it proves the field - and is more explicit why the field matters
Makes clear the mechanism is confirmed and its relationship to the field
Makes clear field not boson gives mass etc
Touches on the impact such knowledge would have (as above), which explains the hype and why seen as pivotal and such effort put in.
Says up front how these all relate and what physicists seek to learn, avoids problem of later refocusing significance from boson (which public believes is important) to field and mechanism.

FT2 ^{(Talk | email)} 01:31, 16 July 2012 (UTC)

I generally like this. In this order it reads much better for a general reader. Some concerns:

... and most favoured Although this is probably true. It is a hard statement to source, and it also borderlines on being POV. Since it does not add much for the lay reader, I think it may be safer to omit it.
the origin of the symmetry-breaking mechanism I fear that this may be a bit jargony for lay readers, who typically do not know what a symmetry is, let alone what symmetry breaking is.

T R 16:53, 16 July 2012 (UTC)

Another remark. Something that generally in the technical literature the term "Higgs boson" can refer to both the field and the particle depending on context. This rather habit goes for all quantum fields, for example "W boson" can refer to either the W gauge field or its quantum. Typically, this does not cause much of problem (because real world occurances of these fields are easily interpreted as superpositions of the particle excitations (possibly including some virtual particles) over a featureless groundstate. This habit is also reflect by the fact that we do not have separate articles for quark and quark field, etc.

The problem with the Higgs is that its ground state (which cannot be expressed as a sum of particle states) is not featureless but plays in important role in the phenomenology of the Higgs. Requiring us to separate the two concepts. Nonetheless, readers may get confused do to the use of language else where.

I am not yet sure what to do about this, but I think we should all be aware of this. One thing we may want to think about is whether we really want separate Higgs boson and Higgs field articles. In the end, it may be easier to treat both in one article like we do with quark.T R 09:29, 17 July 2012 (UTC)

Rename as Higgs field and boson? While that would not be many users' expectation, it would probably be okay once they get over the slight surprise. Or keep as 2 separate articles and cross-link with subsections on each.

As for "most favored" I'd be happy to cite it just from the fact that it is the Higgs field/boson that's incorporated into SM and not some other theory. Also, not trivially, the Higgs field/boson has had a $bn's facility set up to test it first, not some other theory, which strongly suggests it's seen as the most likely or most important one to test initially, with other theories as fallback. That also seems to confirm a preference by physicists for this model of the Higgs Mechanism origins. There's probably some discussion of this in the LHC founding documents, or books on the SM or Higgs. It might take some digging, but I'm fairly sure we can solve the citing issue. So I think it is going to be citeable (which is Wikipedia's criterion). We just have to figure how best to do so. FT2 ^{(Talk | email)} 11:24, 17 July 2012 (UTC)

The main question is what does the "favoured" add information wise? As for being true, I think a couple a years ago, a multi Higgs scenario as in the MSSM may have been more favoured, theoretically. (Arguments constraining the Higgs mass mostly work for the lightest Higgs in a multi Higgs model as well, and the LHC was build to determine the exact nature of the electroweak symmetry breaking in nature.) The only really sense it which the single Higgs model is favoured is because it is the simplest, which we already say.

So again I think it can be safely dropped, avoiding the subjectiveness of the statement.T R 11:42, 17 July 2012 (UTC)

The question it raises is "If there are several explanations, why the huge long-term experimental focus on this one and not the others, as it seems?" (If we say it's because HF/HB are in the SM and other theories for the HM aren't in SM, then that begs the question why those are in SM and others not.) In other words, its value is to answer the reader, why all this focus on testing one specific explanation (or one set of connected explanations for multi-higgs) involving a field and boson/s, if that isn't a specially preferable theory to test first or there aren't special reasons to favor it over others.

As it stands, the Higgs field concept is in SM and its extensions and other theories are not in SM, which tends to suggest physicists prefer the Higgs field concept at present and want to test it first, enough to be worth the effort we've seen to detect the Higgs field's quantum (rather than setting up very high energy experiments to prove other theories). So yes, I would say the Higgs field/boson concept is demonstrably the preferred or leading theory to explain the mechanism, at present. Would you disagree, or are you more concerned about citeability of the statement? FT2 ^{(Talk | email)} 12:15, 17 July 2012 (UTC)

(ec)We already, give the answer to that question: it is the simplest. Many of the other mechanisms involving more complicated Higgs sectors (such as the MSSM or technicolor), effectively reduce to a description with a single scalar field in some limit. However, there is no experimental evidence that favours the single Higgs model. Theoretical considerations (most prominently the hierarchy problem) strongly suggest that the single Higgs field explanation cannot be correct. This BTW is the real reason so much resources have been committed to the LHC. We know something is off about the single Higgs explanation in the SM, but we need experimental input to determine what possible way of fixing this nature uses.T R 12:30, 17 July 2012 (UTC)

"Simplest" doesn't provide a reason at all. Generally we focus on and test things because they are believed most revealing, or most likely to take us forward or be correct, or most likely to provide important data, indifferent whether "simple" or not. The easiest explanation why we're searching for the Higgs boson/s first, given a $10bn or so outlay, is that the HB/s is/are preferrable to search for first. Whether it turns out to be basic SM or supersymmetrical multi-Higgs, the reason we're testing is that the basic concept of a Higgs field/boson(s) and the basic framework of SM with or without extensions, is the leading theory compared to all Higgsless models, at present, and is embedded into SM. The reason is that the Higgs field concept is the leading theory, even if we don't know whether it will prove single or multi boson or which extension to SM (if any) it will favor.

We can probably show this by citation. FT2 ^{(Talk | email)} 12:47, 17 July 2012 (UTC)

Actually, I can cite you sources which contradict the single Higgs being most favoured. For example, the Peskin&Schroeder textbook (one of the most used graduate texts for QFT) states (on page 788): "... This (TR: i.e. EWSB) might be supplied by the vacuum expectation value of a scalar field, or by the more complicated dynamics of a new sector of particles. At this moment, we do not know which hypothesis is preferred." This quite clearly states no particular favor either way, which is still the impression I get from my colleagues working on this.

The misconception that you seem to be working from is that the LHC was build only to test the single Higgs hypothesis. This is not the case, the LHC was designed to test the way electroweak symmetry is broken. Basically, all alternative models predict that something most be observable in at the TeV scale. And many predict at least one scalar particle (sometimes elementary, othertimes composite).T R 13:05, 17 July 2012 (UTC)

Thanks, I appreciate the courtesy of the dialog. I think the misunderstanding is that I see the leading theory as (one or many) Higgs particles and a Higgs field, whether SM or some multi-Higgs extension to SM). When I say the Higgs field is the "favored" or "leading" theory, I don't mean to imply a single-Higgs model, but rather any of the family of models that posits a Higgs field, one or more Higgs bosons, and is compatible with SM or its extensions. You perhaps read my use of the word as meaning that a single-Higgs model is what is "favored", but that's not what I meant or wrote. I was quite careful:

"...it would prove the existence of the hypothetical Higgs field - the ... most favoured of several proposed explanations of [symmetry breaking]..."

"...The leading explanation is that these particles acquire mass by interacting with the Higgs field..."

In other words I've been careful to make clear in writing, that a Higgs field's existence (and some number of bosons but not specified) is what is favored and the leading theory, compared to all theories that don't assert a Higgs field or bosons. I think therefore we're saying the same thing? FT2 ^{(Talk | email)} 13:50, 17 July 2012 (UTC)

Multi higgs bosons also means multiple Higgs fields! (one for every boson)T R 14:14, 17 July 2012 (UTC)

Worth noting but not noted! FT2 ^{(Talk | email)} 15:20, 17 July 2012 (UTC)

A general part of the philosophy of science (which most working scientists follow in some sense even if they've never studied the philosophy of science per se), is Occam's razor, which in science asks that hypotheses or theories be minimalist-- as constrained by observation and their fit with other accepted theories. "A theory should be as simple as possible, but no simpler!" as Einstein put it (and indeed, general relativity is actually mathematically the simplest theory of gravity which is consistent with the constraints of a quasi-Newtonian force, plus special relativity).

The reason for this meta-principle, is that it's always easy to make a theory more complicated by adding epicycles-- or new dimensions or new particles-- to explain something, or make something "pretty" (i.e., mechanistically or mathematically simple). For an especially poignant example of this problem in physics, see supersymmetry, a theory that *doubles* the number of particles that are "supposed to" exist in nature for aesthetic theoretic reasons, even though (unfortunately) not a single one of these extra particles has ever been detected! Scientists don't always follow Occam's razor because it's hard to define "simplicity." Does that refer to the mechanism, the math, or the predicted observables? Supersymmetry people would prefer a theory with "simple" underlying mechanisms, at the expense of a lot more messy complicated observables (those extra particles) that are not seen right now.

So also it is with Higgs and his particle(s). Do there exist these massive scalar boson thingies that act to break the (otherwise perfect) symmetry between massive and massless force bosons? Previously, the question was: do there even exist ANY of these things? (The observational answer, just now "in," is that, yes, thank god, there is at least one). But what reason do we now have to posit additional ones? This article should probably address that question in a paragraph or two. Note from the quotes above that messy theories with many unseen types of particles that serve no purpose but symmetry aesthetics "bother" some theorists more than they do others. That's a matter of pure taste, since observation always has limits and places to hide postulated entities. All that is one of the debates at the heart of string theory. S B H arris 17:17, 17 July 2012 (UTC)

News and reliable sources

Currently the article contains quite a few citations to news sources. Considering the number of factual errors typically contained in those reports, I do not think that they can be considered as reliable sources for this article. (Especially, since journalists writing those stories may very well be using wikipedia for part of their information!) I think that most of these should be replaced with higher quality sources. Some exceptions may exist, such as newspaper columns by notable physicists.T R 09:37, 17 July 2012 (UTC)

Agreed. That's the second bullet in WP:NEWSORG, BTW. A. di M. (talk) 12:12, 17 July 2012 (UTC)

Agree also, with the caveat that quite a few non-contentious and non-technical points are not so much of a problem. However reports where a reader reasonably expects technical accuracy should be high quality sources. FT2 ^{(Talk | email)} 12:27, 17 July 2012 (UTC)

Intro edit - eyeballs?

Any chance of eyeballs on this edit I made [2]? I've tried to put the explanation of the particle first, then the explanation of its name. I really wanted to link two sentences or reduce repetition, but couldn't find a good way to do so. Best I have as an alternative so far is:

"The existence of a Higgs field and its associated Higgs boson would be the simplest of several ways to explain how certain elementary particles have mass. The Standard Model says these particles gain mass by interacting with the Higgs field, which has non-zero strength everywhere, even in otherwise empty space."

Not really brilliant prose. Improvements? FT2 ^{(Talk | email)} 09:54, 14 July 2012 (UTC)

Readable sources (for laymen) about the connection between Higgs field and Higgs boson are:

Flip Tanedo: Who ate the Higgs?; Helicity, Chirality, Mass, and the Higgs
Matt Strassler: The Higgs FAQ 1.0; The Standard Model Higgs

Maybe something could be used to simplify or better formulate the introductory parts. --D.H (talk) 10:05, 14 July 2012 (UTC)

That's the best formulation/prose I've seen so far for the lead. Well done. Dickdock (talk) 11:47, 14 July 2012 (UTC)

The intro has developed an error: "The Higgs mechanism is the simplest of several proposed ways to explain why certain other elementary particles have mass". That's incorrect. The Higgs mechanism is essentially considered confirmed; the question then is what causes the mechanism to happen. It's the Higgs field and its related force carrier that is the correct subject of the clause "is the simplest of several proposed ways to explain" how that mechanism is realized. FT2 ^{(Talk | email)} 20:52, 15 July 2012 (UTC)

Incidentally, "force carriers" usually refers to the spin-1 bosons that mediate the gauge interactions (i.e. W, Z, photon and gluon). I've never seen the Higgs boson referred to in that way. Ptrslv72 (talk) 22:36, 15 July 2012 (UTC)

Why do physicists dislike the God Particle?

Currently, the introduction states:

Although the proposed particle is both important and elusive, the epithet is strongly disliked by physicists, who regard it as misleading exaggeration[10][11] since the crucial focus of study is to learn about the Higgs field - the boson is a means to that end - and because the field rather than the boson theoretically gives mass to some other particles.

I am really unconvinced by the explanation since the crucial focus..., which sounds as if the reason why physicists dislike the epithet was that it does not do justice to the distinction between Higgs boson and Higgs field. I don't think this is the case: as both references 10 and (especially) 11 make clear, the main reason why physicists don't like the name is that it lends religious overtones to a subject that has nothing to do with God. Unless somebody can provide sources in support of the current explanation of the dislike, I would be inclined to remove it. Cheers, Ptrslv72 (talk) 16:26, 16 July 2012 (UTC)

What's missing is the "religious overtones" sense (the implication that "this is the pivotal and mystical particle that if it exists, explains all"). The rest is valid, but this aspect is not present at all, and should be made clear. FT2 ^{(Talk | email)} 12:33, 17 July 2012 (UTC)

I am not sure that "the rest is valid". The way the sentence is written now, it almost sounds as if "God field" would be ok whereas "God particle" is not ok. The distinction between field and particle is important elsewhere in the lead, but it is not the reason why physicists dislike the nickname (this appears to be just an interpretation of yours which is not supported by the references). Ptrslv72 (talk) 12:58, 17 July 2012 (UTC)

Tried to fix this. FT2 ^{(Talk | email)} 13:40, 17 July 2012 (UTC)

I am missing my copy of Lederman's book The God Particle that started all this. It's a very good book, however, and I recommend it. But let us remember that it was written in 1992 or so when there was a real possibility that the Superconducting Supercollider (SSC) would be cancelled in Texas (as eventually it indeed was), and the book was written in part to raise popular awareness of the physics that the SSC was supposed to produce, which was (of course) the Higgs. Lederman's later comment that he wanted to call it the "godamn particle" should be taken in light of Lederman's sense of humor and playfulness. He's a raconteur if nothing else, and not beyond re-spinning this. Originally the book argued for finding Higgs as a way that the common US taxpayer (most of whom are religous) could make a connection with the ways of God-- by paying for the SSC!

As I remember, in Lederman's book this included not only an argument about the fundamental particles and their mass, but also the Higgs' role in the inflation of the early universe, as originally postulated by Guth in 1980. So Higgs would have had a major role in explaining creation, too. That's god-like. In 1992 (the book published in 1993) I'm not sure it had yet been determined that the Higgs field could not have caused Guth's inflation, as Guth originally had suggested in 1980 that it had. So THAT 1992 reason for calling Higgs "The God Particle" has (by now) been forgotten. Somebody is going to have to read Lederman's book to see (again, my copy is on loan to somebody). However, it's highly referenable, since Lederman is the guy who is to blame for this term. But the Higgs boson's supposed role in cosmic inflation, plus Lederman's desire to have Believers pay for the SSC, surely both played a role in his choice of a moniker for the thing. And those facts should go in Wikipedia. S B H arris 17:33, 17 July 2012 (UTC)

Since the article talks about the source of the common name 'the god particle', it should mention Lederman has said he wanted to call it the 'goddamn particle'. Besides the author good reference to cite is an NPR interview with Dr. Victoria Martin of Edinburgh University [3] (who studied under and worked with Higgs and has current research at CERN):

SIEGEL: I want to ask you about this particle's nickname, the "God particle." What did Higgs, who I've read is an atheist, think about the nickname the "God particle"?

MARTIN: I'm sure - I actually haven't ever asked him this directly, but I'm sure he doesn't like it. Almost all particle physicists detest that name. It was actually Leon Lederman, who's a Nobel laureate, that came up with it. But he was trying to call it "that goddamn particle," and that wasn't allowed by the publishers so it became the "God particle." So the name stuck and I think it's fine because then people know what we're talking about. But secretly, all of us hate the name, the "God particle." [4]

And here is a quote from Higgs on the subject:

"...Higgs himself is no fan of the label. "I find it embarrassing because, though I'm not a believer myself, I think it is the kind of misuse of terminology which I think might offend some people."

It wasn't even Lederman's choice. "He wanted to refer to it as that 'goddamn particle' and his editor wouldn't let him," says Higgs."[5]

Klolo9 (talk) 05:23, 19 July 2012 (UTC)

Some subtleties with regard to what particles are massless without a Higgs field.

There are some subtleties with regard to the masses of particles, which seem to be confuse some editors here:

The particles that acquire a mass through interaction with the Higgs are: all elementary fermions (with possible exception of the neutrinos) plus the the W and Z gauge bosons.
However not all these particles will be massless if there were no Higgs field in the Standard Model.
The reason for this that if the quarks are massless, the strong dynamics of QCD will break the electroweak symmetry with the pions acting like goldstone bosons (and become the longitudinal modes of the W and Z bosons, which acquire a mass.)
Consequence: If there were no Higgs field in the SM, all elementary fermions would be massless, but the W and Z bosons still would have a mass.

Now this does not need to be discussed in this article. However, it does force us to be very careful in phrasing sentences about which particles acquire mass and which don't. T R 15:27, 18 July 2012 (UTC)

Well, if right-handed neutrinos have a Majorana mass they would still have it without the Higgs mechanism (though without the Yukawa coupling between them, left-handed neutrinos, and the Higgs field, they would couple with nothing at all and so there'd be no way to make or detect them). A. di M. (talk) 07:30, 19 July 2012 (UTC)

But the SM does not have right-handed neutrinos. But, yes neutrinos are another point of subtlety, where we simply do not know yet how they get a mass.T R 08:35, 19 July 2012 (UTC)

Well, the most straightforward thing would be adding right-handed neutrinos (with all quantum numbers equal to zero) and couple them to left-handed neutrinos via Yukawa coupling, the same way it's done with up-type quarks, with the PMNS matrix as the analogue of the CKM matrix. A. di M. (talk) 13:17, 19 July 2012 (UTC)

Yes, it would, but there are alternatives. Neither are in the SM though.T R 13:38, 19 July 2012 (UTC)

Where would it go in the Standard Model "grid"?

While the results so far only indicate a boson of some sort was found, the news (whatever it's worth) tells me it's likely to be the Higgs boson. In the Higgs Boson#Theoretical properties section, the interaction diagram includes the Higgs boson. And in the Higgs Boson#General description section, there's a sidebar for Template:Standard model of particle physics, which doesn't include the Higgs boson, which is reasonable since it hasn't been confirmed yet. But given how long the search has been, there must already be some sort of arrangement physicists have in mind. What would it look like? The only thing like that I've seen is on Wikipedia is at Standard Model#Higgs boson. I think it would be useful to have a similar (or same?) diagram on the Higgs boson article, to clarify to laymen such as myself how it is expected to fit, generally. 24.57.210.141 (talk) 23:52, 18 July 2012 (UTC)

As far as I know, the fermions can be organised into three generations, with one pair of quarks and one pair of leptons for each generation. But there is no arrangement for the bosons that I'm aware of, the current table just lists them alongside the fermion generations because it fits visually, not because it also fits through physical properties. So it doesn't really 'fit' anywhere in particular, and the question of where to add it to the table is really one for Wikipedia editors to answer, not scientists. CodeCat (talk) 00:38, 19 July 2012 (UTC)

Article should mention the Higgs singlet

The article should mention the Higgs singlet. — Preceding unsigned comment added by Ocdnctx (talk • contribs) 00:48, 27 July 2012 (UTC)

Higgs production

I modified TR's entry on Higgs-strahlung because I thought that the term refers to the process in which you still have a gauge boson in the final state (i.e., the gauge boson emits a Higgs, it does not decay into a Higgs - indeed "strahlung" is German for "radiation"). However, on a second thought, it might well be that the process in which a real Z decays into a Higgs boson and a fermion pair was also referred to as Higgs-strahlung in the nineties (i.e., at the time of LEP1). If that can be proved with a reliable source we can restore TR's sentences on the subject. Ptrslv72 (talk) 09:35, 27 July 2012 (UTC)

I think you are right. Good call.T R 09:57, 27 July 2012 (UTC)

Technical request - what's correct here?

@TimothyRias - Following some recent edits of yours I edited the rest of the intro to bring it into line, and you've reverted that to what you describe as an "error free" version. Since my edits reflected your own, can you take another look and figure what we ought to be saying:

1) You edited: from: "the Standard Model says some particles that have mass would be massless" to: "the Standard Model says that elementary fermions such as quarks and electrons would be massless".

If this is correct then (a) other references to "some particles" or "elementary particles" should also be edited to "elementary fermions", and (b) the assertion should be cited. You reverted.

2) Also your comment in a previous section describes the subtleties in this area - which particles "get mass" and what that means, to what extent it's accurate. Does this imply that the edit you made from "some particles" or "elementary particles" to "elementary fermions" in the mass footnote is insufficiently precise as well, and should also be firmed up?

If so could the "terminology" section be a good place for that? As it covers "basic terms knowledge needed for the topic" - maybe the Higgs mechanism paragraph could outline what gains mass from HM?

3) Again the mass footnote, what's actually known at this point where HF is not proven, is that a HM exists. It's suspected to be due to one or more HF but this isn't proven yet and other ways to generate a HM exist or could exist. The mass note stated "Without some source of the Higgs field, the Standard Model says..." but this isn't the best note on the issue. It essentially deals with the case that SM/HF is correct - but at present it need not be.

The more useful explanatory note here isn't to write "without HF, SM says these particles would be massless" which is accurate but over-limited and merely a comment on one specific solution not yet proven (although believed to be correct). The better comment is that "without some source of HM, any current model will say these particles are massless".

Ie, the more pointed requirement is to make clear in the footnote, that a criterion for any credible theory (and this seems to apply to all theories currently deemed credible) has to provide specifically, a source of HM. The existing wording sidesteps that core point by just discussing what SM requires, but at a point where SM is itself one of a number of theories and the whole aim is to find if SM or something else is right. In these circumstances it's better to explain what any candidate theory of particle physics has to provide for - namely it must show some viable explanation for the source of HM.

4) As noted earlier in talk page points out "multiple HB means multiple HF" so we can't say it's just a single HF. I edited the lede to reflect this, from: "The leading explanation is that these particles acquire mass by interacting with the Higgs field, which has non-zero strength everywhere" to: "The leading explanation is that one or more Higgs fields exist, having non-zero strength everywhere, and these particles gain mass by interacting with it". You reverted to "a field" (singular).

While basic SM is the current explanation, if it's correct that some quite favored SM extensions predict multiple HF, then the lede should probably say "one or more". It wouldn't hurt and would then be much clearer that this could be the case for some outcomes that involved a HB (ie SM extensions) and it wouldn't surprise the reader when we later say there could be multiple HF even if HB was found.

Can you take a look at these? Thanks :) FT2 ^{(Talk | email)} 00:40, 19 July 2012 (UTC)

1) See my comment above. Although the Higgs field gives mass to all massive particles, not all particles become massless if there is no Higgs field. The change you made was incorrect.

2)No, my remark in the mass footnote is precise. (Without a Higgs field all elementary fermions are massless according to the SM.)

3)There is a problem with saying "without some source of HM". The SM model already has a source of HM build into it. If the quarks are massless, the strong dynamics of the quarks will break the Electroweak symmetry on their own (however the W and Z would be much lighter (~10 MeV) than observed (~100 GeV)). Since the quarks cannot get a mass without breaking the electroweak symmetry, this means that there will always be a source of the Higgs mechanism.

Moreover, even if there is a source of the HM, if it does not couple to the fermions they will still be massless. E.g. this is the case in the SM without a Higgs field.

4)I think including the possibility of multiple Higgs is in the lede over complicates things. It generally makes the statements much harder to digest. I think we are pretty safe in saying the leading explanation is a single Higgs field (even if it is not really favoured that much). We can discuss possible extensions with multiple Higgses, or composite Higgses, or whatever further down in the article, where there is more room to provide the appropriate context.

T R 07:27, 19 July 2012 (UTC)

Update - I've tried to improve a couple of technical points (I'll come back to others later perhaps). Specifically as far as I can understand, other mass generation mechanisms exist (the article note refers to these already) and the term "Higgs mechanism" in the broadest sense is a general term for symmetry breaking mechanisms. For example, if it were the only kind of symmetry breaking mechanism them statements found on physics pages on the theme of "HM in SM almost always refers to EWSB" would be redundant, as it couldn't possibly refer to anything else. From the Higgs mechanism article (nicely updated - good work!) I draw the point that in the Standard Model, HM/EWSB is responsible specifically for the mass of certain gauge bosons, but not all of them. On the assumption that's correct I've also edited this article a bit. Can someone check these are technically ok? Thanks. FT2 ^{(Talk | email)} 16:22, 6 August 2012 (UTC)

I've adjusted your edits a bit. I'll try to explain here.

The Higgs field does 2 things in the Standard Model:

It breaks the SU(2)xU(1) electroweak gauge symmetry to the U(1) gauge symmetry of electromagnetism through the Higgs mechanism. In the process giving mass to the W and the Z bosons, the weak gauge bosons. (All other gauge bosons are massless)
By interacting with the fermions, the Higgs field gives mass to the elementary fermions. (i.e. all particles that interact with the Higgs have mass, and all elementary particles with mass, get that mass through interaction with the Higgs.(with a possible caveat for right handed neutrino's, but they are not part of the SM in the first place.)) Somewhat confusingly, this second part is also sometimes referred to as the Higgs mechanism (because it is made possible by the Higgs field being non-zero in the ground state.

Note that the above is not true for all possible sources of electroweak symmetry breaking. For example, QCD with massless weakly interacting quarks, also breaks the EW symmetry. In that case, the corresponding goldstone bosons are the pions, and they get absorbed by the weak gauge bosons to provide them with mass. However, the fermions do not get a mass. Vanilla technicolor has the same problem.

I think for this article (and especially the lede) we should avoid getting side tracked by discussing what is called the Higgs mechanism, and what is not. Instead the focus should be, what does the Higgs field do? (i.e. give mass to all massive elementary particles).T R 11:32, 7 August 2012 (UTC)

ATLAS 5.9sigma, CMS 5sigma

ATLAS published new results and improved the local significance at 126 ± 0.4 (stat.) ± 0.4 (sys) GeV/c² to 5.9sigma

http://arxiv.org/abs/1207.7214

And CMS reached a local significance of 5sigma at 125.3 ± 0.4 (stat) ± 0.5 (sys) GeV/c²

http://arxiv.org/abs/1207.7235

Submitted to Physics Letters B. --D.H (talk) 08:31, 1 August 2012 (UTC)

New "mathematics" section

The formulae in FT2's new section don't seem right to me. In particular, I've never seen a factor 1/Sqrt[2] in the definition of the SU(2) doublet (the first equation). As a result of that factor, the kinetic term and mass term for the complex scalar fields phi^+ and phi^0 in the second equation are not canonically normalized. Moreover, the third equation implies v ~ 246 GeV, but then the fourth equation implies e.g. m_top = (G_u)_33 v, which is incorrect (with that normalization of v, it should be m_top = (G_u)_33 v/Sqrt[2]). I think we should remove the 1/Sqrt[2] from the first equation and define the vev as <phi^0> = v/Sqrt[2]. Moreover, the statement that v "is the only parameter in the Standard Model which is not dimensionless" is clearly incorrect (mu^2 has dimension of a mass as well, and it is arguably the "true" fundamental mass parameter of the SM). Cheers, Ptrslv72 (talk) 12:33, 20 August 2012 (UTC)

Note that it says only free parameter. If you take v as a free parameter, then the Higgs mass is not a free parameter.T R 14:21, 20 August 2012 (UTC)

"free" was added after I wrote the comment above. Ptrslv72 (talk) 14:46, 20 August 2012 (UTC)

Also, the description of the "mexican-hat" potential is incorrect. The potential is plotted as a function of the real and imaginary parts of phi^0, not the real parts of phi^0 and phi^+ (obviously, a non-zero vev for phi^+ would break charge conservation). Ptrslv72 (talk) 12:37, 20 August 2012 (UTC)

As you wish, but note that the real part of phi^+ is (phi^+ + phi^+^*) = phi^+ + phi^-, which is in fact neutral. ;).T R 14:21, 20 August 2012 (UTC)

It's not "as I wish", look at the axis labels in the picture. And no, phi^+ + phi^- is not neutral, it is not even an eigenstate of the electric-charge operator Q. Ptrslv72 (talk) 14:36, 20 August 2012 (UTC)

\phi ^{\dagger }\phi =(Re\phi ^{+})^{2}+(Im\phi ^{+})^{2}+(Re\phi ^{0})^{2}+(Im\phi ^{0})^{2}

. So, it does not matter which two you take to plot the potential.T R 14:53, 20 August 2012 (UTC)

Why do you think it doesn't matter? Check page 16 of the lecture notes I already linked below: the electric charge is conserved (and the photon remains massless) only if the vev is either all in the "up" component of the doublet or all in the "down" component of the doublet. We have chosen the hypercharge in such a way that the "up" component is charged and the "down" component is neutral. Hence, the vev must be all in the "down" component, which is why, when we plot the potential to show where the vev comes from, we set the "up" component to zero. Ptrslv72 (talk) 16:01, 20 August 2012 (UTC)

For any other vacuum state there would simply be another conserved U(1) charge which we would call Q. So, no it does not matter at all.T R 16:15, 20 August 2012 (UTC)

With the notation that you used until your latest changes (i.e. phi_up = phi^+, phi_down = phi_0 and Y=1) you were clearly implying that Q was the usual I_3 + Y/2, thus the vev had to be all in the bottom part. And in any case, the caption should be consistent with the figure, where phi_RE and phi_IM clearly refer to the real and imaginary part of one component of the doublet. Ptrslv72 (talk) 17:00, 20 August 2012 (UTC)

One more comment: in order to get the gauge boson masses given in the third equation, the second and third term in the covariant derivative (in the second equation) should each be divided by 1/2. To be more precise, this factor could still be hidden in t^a for the SU(2) gauge boson, but it definitely has to be there for the U(1) gauge boson. For a self-consistent set of formulae for the SM Higgs sector, see e.g. chapter 2 of these lecture notes. Ptrslv72 (talk) 13:19, 20 August 2012 (UTC)

And one more: since phi is a complex doublet, the kinetic term in the Lagrangian is (D^mu phi)^dagger D_mu phi, not [D_mu phi]^2 as is currently written. Ptrslv72 (talk) 13:27, 20 August 2012 (UTC)

TR, I suppose you are thinking of eq.(20.110) of Peskin-Schroeder. However, in that equation h(x) is a real field, thus the 1/Sqrt[2] is correct (so that e.g. the kinetic term in the Lagrangian reads 1/2 d^mu h d_mu h). On the other hand, in the first equation of our section phi^+ and phi^0 are complex fields, so the factor 1/Sqrt[2] must not be there (e.g., the kinetic term for a complex field is d^mu phi^* d_mu phi). Ptrslv72 (talk) 14:02, 20 August 2012 (UTC)

Yukawa couplings

TR, I see a problem in the formula for the Yukawa interactions. The Yukawa couplings are 3x3 matrices in flavor space. You can rotate the quark fields to a basis where the matrices are diagonal, but then the interaction of the charged component of the Higgs with one up-type quark and one down-type quark contains the CKM matrix. In your formula, on the other hand, the charged-Higgs interactions with quarks are flavor-diagonal. Cheers, Ptrslv72 (talk) 17:13, 20 August 2012 (UTC)

You are right (as so often). I jumped the gun on writing the whole thing diagonally. I sort of hoped to avoid mentioning the CKM matrix at all but it seems unavoidable.T R 20:38, 20 August 2012 (UTC)

Also, the charged-Higgs interactions don't look right: if phi^+ = phi_1 + i phi_2, then the second term in the first line of the Lagrangian destroys a phi^+ and an up and creates a down, while the second term in the second line destroys a phi^- and a down and creates an up. Both violate charge conservation. On the other hand, the second term of the third line is OK (it destroys a phi^+ and an electron and creates a neutrino). We should also check that the hypercharge adds up correctly in the neutral-Higgs interactions, and that the relative signs of the six terms in the lagrangiane are all correct (the latter are all fixed once we fix the signs of the mass terms and the relation between mass and Yukawa coupling). Cheers, Ptrslv72 (talk) 17:46, 20 August 2012 (UTC)

This is why I love collaborative working. Thanks TR and Ptrslv for catching these; can someone check Standard Model (mathematical formulation) to be sure any improvements here are reflected there as well? It was a direct text lift of work added by others (as noted in the edit summary); I understood its relevance to this article enough to bring it over but lack technical skills for editing and correcting gauge theory math. FT2 ^{(Talk | email)} 22:20, 20 August 2012 (UTC)

Mmmh I'm not so keen to touch the "mathematical formulation" article. As we've just seen, virtually every equation of the paragraph that you imported from there contained some inaccuracy. I suppose it's fair to expect that the rest of the article will be just as bad. Correcting it would require a lot of work, and anyway a reader interested in that level of mathematical detail should rather go for a proper scientific source (I mean, a textbook or some lecture notes). I know that you don't like this approach, but I would rather remove the link to the "mathematical formulation" article and just make sure that what we have here is fully correct. Cheers, Ptrslv72 (talk) 00:18, 21 August 2012 (UTC)

Darn, that's annoying. You're right in second guessing how I feel on that (even though disappointed to find it wasn't top notch) - we should have that article, it should be in good condition or at least error free if not perfect, and should be linked (lots of "shoulds"). The "lots of work" reason isn't too persuasive (many articles take lots of work) nor the "should use a textbook" reason (we have many technical articles in math and elsewhere, no clear reason not to cover this encyclopedic topic even if technical). Also it's nicely pitched at a good level of description. The only issue is, is it actually misinforming people to the point of "more harm than good"? I can't judge how badly a physicist would rate the "some inaccuracy". If it's capable of giving a decent idea but not 100% solid, then a tag on the page is definitely needed to warn readers, if it's all horribly wrong then chunks of the text will need deleting as well, in the worst case AFD is called for (and see if anyone can fix it). If it's not at that depth of disaster, notable encyclopedic content shouldn't be deleted unless we really can't do anything to make it useful on balance. Even leaving it linked helps to incrementally improve the wiki - this discussion is a case in point.

I suspect you might favor accuracy or nothing, but semi-accurate with tagging is often used as articles are constantly developed and may be substandard a while before someone has the impetus to fix them. Can the article in question be hat tagged in a way that adequately represents the issues, and alerts readers to the concerns? FT2 ^{(Talk | email)} 12:09, 21 August 2012 (UTC)

The "lots of work" reason is fully persuasive for what I am concerned: I have my own work to attend to on the side, and just fixing the short snippet that ended up in this article took us a full afternoon. This said, we should ask ourselves what kind of reader an article such as Standard Model (mathematical formulation) is aimed to. It is a reader who already has some knowledge of quantum field theory, otherwise all the formulae contained in the article will look meaningless to him/her. This already narrows the readership down to physics students, who usually have access to textbooks and lecture notes and should know better than looking for technical information on Wikipedia. But let's assume for the sake of the argument that the article is meant as a collection of formulae to be used as a reference by those who do understand them. Then the article makes sense only if all of the formulae are correct. Wrong signs or wrong factors of two may look trivial to the layman, but they make the formulae useless precisely to the kind of reader who might be interested in them. And again, making sure that a technical article is all correct (and that it uses a consistent notation throughout the different sections) requires a non-negligible effort which could only be provided by the minority of editors who have a working knowledge of the subject. Not to mention the fact that, once an article is cleaned up, it requires constant policing to make sure that mistakes are not reintroduced by well-meaning but non-expert editors.

To be entirely honest, I even wonder if it was a good idea to introduce the "Mathematics" section in the Higgs boson article. The readers who can understand the formulae already know all of this stuff, and they most likely have access to proper textbooks. For all the other readers the section could be off-putting, and I wonder how many of them will just stop reading there and miss the relevant (and much more accessible) information given below. Cheers, Ptrslv72 (talk) 13:14, 21 August 2012 (UTC)

I am somewhat ambivalent to having the section there. I see some virtue to having there. To readers who are able to process the mathematical notation it can be very clarifying, and I do believe there is a non-negligible subset of readers that can process this, but that does not know this already. Basically, this includes everybody that worked on a graduate degree in theoretical (not necessarily high energy) physics in past couple decades, and similarly people with degrees in high energy physics but no longer active as a physicist. With the recent media attention these people are very likely to look this article up. (Higgs physics is one of those areas that most physicists feel they should know what it is about, but only few really do.)

That being said I completely share your worry about having an off-putting while of impenetrable mathematics right in the middle of the article. It definitely is couple registers more technical than the level I was aiming for with the production and decay sections. One thing we may want to consider is having the section later in the article.T R 14:12, 21 August 2012 (UTC)

Moreover, the new section only shows how the SM gauge bosons and fermions acquire mass through the Higgs mechanism. Ironically, no mention is made of the Higgs boson itself, which after all should be the subject of the article. I wonder if this section shouldn't rather be moved to the Higgs mechanism article (which BTW is another article I'm afraid to touch lest it becomes a burden). Cheers, Ptrslv72 (talk) 13:29, 21 August 2012 (UTC)

This is also a good point. The Higgs mechanism is something a little more general than the way it is implemented in the Standard Model. It simply explains how spontaneous breaking of a gauge symmetry leads to the gauge bosons acquiring a mass through absorption of the goldstone bosons. In particular it does not necessarily include the fermion mass generation that is something very specific to the SM. Hence Higgs mechanism may not be the best home for this.

Currently, this article covers both the Higgs boson and the Higgs field. So, I think there is some room here to explain how the Higgs field interacts with the SM. If it stays here, we may need to expand with some information about where the Higgs boson itself comes into the story.T R 14:12, 21 August 2012 (UTC)

Edits since above

Good comments, thank you. It helped a lot to understand the perspectives held. Edits made:

Math moved to end. I agree with above, also a "technical section" allows for other technical information without forking in future.
Noticing the start of a separate Search for the Higgs boson article, I've tried to created a decent intro for it, moving over relevant material, recasting to focus mainly on the search, and then cutting down this article's length greatly, in summary style.
The issue above - the paragraph that got moved between History and Theoretical properties because it's a bit of both - resolved I think. About 1/2 of theoretical properties was actually closer to theoretical background to why the Higgs (or something having that effect) was necessary. Before, this seemed to duplicate the "History, hopefully now it doesnt feel that way as much (but see below).

Possible "to do" -

Merge, with discretion, some of Introduction to the Higgs field - low quality in parts and much less need now for an "introduction" as we've written one here.
The "Overview" section was useful but with the forked "search" sub article and simpler (yet complete) explanation in "history" and "theoretical properties/theoretical need for the higgs", do we still need this section at all? Can we merge any useful content from it into other sections (they seem almost as easy to understand as the "Overview" anyway).
Add a summary of this article key points to the background section in the Search for the Higgs boson article.
The "History" and "Theoretical properties" section still have duplication. Is it possible the paragraphs in them are overly duplicated or could be improved by some judicious move-and-merge of their text between them? Or no need now the latter is clearly explaining a different point (by having a new subsection for that part of it)
Some mention (briefly) of Yang-Mills theory in the "History" section? This was where the problem of symmetry breaking and masslessness first appeared, or so it seems, years before. That article has some brief but useful history text ready to use. Can someone do this, to ensure it's correctly characterized? Also relevant for wikilink purposes: articles on Yang-Mills existence and mass gap and Yang-Mills-Higgs equations.

Any errors of precision, hopefully minor and easily fixed. FT2 ^{(Talk | email)} 05:26, 23 August 2012 (UTC)

New paragraph in the history section

I had missed the fact that FT2 moved a paragraph from "theory" to "history", I think this doesn't work. The paragraph (now the second in the "history" section) refers to the Standard Model, the W and Z bosons and the issue of fermion masses as the "source" of the problem whose solution came from the Higgs mechanism. In fact, the 1964 papers by Higgs and the others only addressed the problem of giving mass to the gauge bosons in a generic abelian model. The Standard Model was not proposed until three years later. I think that the "history" section should try to respect the chronological order of the various contributions, whereas the "theory" section we can take more liberties and present the various issues from a modern point of view. Cheers, Ptrslv72 (talk) 20:22, 20 August 2012 (UTC)

It works. I was glad to find the technical treatment in another article, and that it was at about the right level technically to use here. I noticed the probable anachronism, where the explanation why a mechanism was needed, was in terms of experimental observations and SM theories from later in the timeline.

I felt that overall the purpose of that paragraph was to explain why there was a theoretical issue, and what problem HM solved, in a bit more depth. It's not really a discussion of the theoretical properties, so much as a discussion of a historical problem with past theories and the context of the 1960s papers onward. It's unfortunate that it was cast in terms of non-sequential evidence, but overall the article significance of that paragraph seemed to be explaining a historical situation in theory development, and not describing the currently-theorized properties of the particle/field. Hence my move after inserting it, to the history section. If anyone can suggest a "fix" then go ahead, if not then Ptrslv's logic is fine. FT2 ^{(Talk | email)} 22:14, 20 August 2012 (UTC)

Correct capitalization?

Hi, nuclear physics graduate student here. I'm just wondering why the particle is typed "Higgs boson" instead of "higgs boson." I mean, bosons in general are named after a scientist, just like the "higgs." Should we be typing it in lowercase to remain consistent? If Wikipedia moderators agree, could we change the article's title to higgs boson? Thanks. — Preceding unsigned comment added by 107.4.189.194 (talk) 23:57, 4 August 2012 (UTC)

It is standard practice in the literature to capitalize Higgs. As it should be since Higgs is a proper name. Some other examples that follow that rule and are likely familiar are Feynman diagram, Dyson series, Weinberg angle. There are many such examples. Dauto (talk) 03:58, 5 August 2012 (UTC)

My experience is that complete names used as separate words retain their capital letters, and compound or derived terms start to lose them. Therefore, we have bosons that follow Bose statistics, and Goldstone bosons (Goldstone's name remains a separate word). I generally see Higgs capitalized. Higgsino can go either way. --Amble (talk) 19:37, 8 August 2012 (UTC)

What about Goldstonino?--88.64.10.112 (talk) 23:02, 19 August 2012 (UTC)

Following the principle I outlined, (G|g)oldstino should start to lose its initial capital as it takes on life as a distinct word independent of the name Goldstone. In this, it's similar to Higgsino. Looking through the literature, that's what I see: it is capitalized or not rather haphazardly, about half the time each way. That's consistent with my expectation. --Amble (talk) 22:12, 2 September 2012 (UTC)

TR - revert?

@TR - can you reconsider this revert.

Original:	The Higgs field—if it exists—is not responsible for all mass, but only for the masses of elementary particles. For example, only about 1% of the mass of baryons (composite particles such as the proton and neutron) is due to the Higgs mechanism acting to produce the mass of quarks. The rest is due to the mass added by the kinetic energies of quarks and the energies of (massless) gluons of the strong interaction inside the baryons. Without the Higgs field, the Standard Model says that elementary fermions such as quarks and electrons would be massless.
Proposed:	The Higgs field—if it exists—is not responsible for all mass, but only for the masses of elementary fermions such as quarks and electrons, as well as the W and Z gauge bosons. Without the Higgs mechanism these particles would be massless. However only about 1% of the mass of baryons (composite particles such as the proton and neutron) is due to the Higgs mechanism giving mass to their quarks or other components. The other 99% arises due to spontaneous breaking of chiral symmetries within the strong nuclear interaction instead, in conjunction with the kinetic energies of quarks and the energies of (massless) gluons of the strong interaction inside the baryons.

Without adding length (beyond names of entities already alluded to) or "junk" info, the edit improved flow:

The original bounced back and forth - it mentioned the Higgs field and weak force, then bounced to strong force, but then goes back to the weak force just to name the particles it affects. Illogical order, better to name these in the original mention.
The original states 1% is due to HF and states the source of the rest - but only in terms of (arbitrary sounding) sources of energy. I see we have an article (stub but that's ok) on the exact effect it's talking about, that already states it covers "99%" of the mass of those same particles, and gives a name rather than just a list of energies. Worth linking to and giving a name.
The note lists particles given mass by HF, but just as a list, and apparently incomplete - the note says fermions gain mass, the article says fermions and massive gauge (W/Z) bosons gain mass. Consistency matters. As HF (if proven) is responsible for the mass of any particle acquiring mass due to EWSB (almost by tautology) it's easier to say that and identify the particles as examples, which is appropriate for a note anyway. If this isn't correct it doesn't affect the other 2 points.

The original was low quality. Not fatally broken, but certainly for a brief note, fixable issues capable of better flow. FT2 ^{(Talk | email)} 21:41, 25 August 2012 (UTC)

Your edit, add a bunch of unexplained jargon for no particular good reason.

To your first point, that is much better fixed by just leaving out the last sentence (which was just a leftover from me fixing earlier bad edits to this note).
To your second point. Note that that article is unsourced (and so was your statement). The effect is not called "chiral symmetry breaking". In fact, saying that baryons acquire mass due to chiral symmetry breaking is rather weird. To me the opposite relation is more sensible "chiral symmetry is broken due to baryons acquiring a mass". (Also note that because of the Higgs field there is no chiral symmetry in the first place).
To your third point. I have explained this to you already. The note said that without the Higgs field, the fermions would be massless. This correct and complete, because in the standard model without a Higgs field, the W and Z boson would still acquire a mass (albeit a much lower one) due to breaking of chiral symmetry in the strong sector. (The corresponding goldstone bosons, the pions, would get eaten be the gauge bosons to provide the longitudinal modes).

T R 11:30, 26 August 2012 (UTC)

error in box showing paths of boson formation

Below is the text in question:

Feynman diagrams showing the cleanest channels associated with the Low-Mass, ~125GeV, Higgs Candidate observed by the CMS at the LHC. The dominant production mechanism at this mass involves two gluons from each proton fusing to a Top-quark Loop, which couples strongly to the Higgs Field to produce a Higgs Boson.

Left: Diphoton Channel: Boson subsequently decays into 2 gamma ray photons by virtual interaction with a W Boson Loop or Top-quark Loop. Right: 4-Lepton "Golden Channel" Boson emits 2 Z bosons, which each decay into 2 leptons (electrons,muons). Experimental Analysis of these channels reached a significance of 5 sigma.[68][69] The analysis of additional vector boson fusion channels brought the CMS significance to 4.9 sigma.[68][69]

Note: I believe that in the last sentence the CMS significance should be changed to 5.9 be consistent with this sentence elsewhere in the article (under the heading "Discovery of New Boson"):

On July 31 2012, the ATLAS collaboration presented additional data analysis on the "observation of a new particle", including data from a third channel, which improved the significance to 5.9 sigma (1 in 588 million chance of being due to random background effects) and mass 126 ± 0.4 (stat) ± 0.4 (sys) GeV/c2,[3] and CMS improved the significance to 5 sigma and mass 125.3 ± 0.4 (stat) ± 0.5 (sys) GeV/c2.[2]

This is a very minor error in an otherwise wonderful article!!! — Preceding unsigned comment added by 50.53.129.6 (talk) 07:37, 3 September 2012 (UTC)

There's no error, the significance of the CMS result is different from the one of the ATLAS result. Cheers, Ptrslv72 (talk) 10:06, 3 September 2012 (UTC)

"Tentatively observed" in the opening sentence

User user:Bhny replaced the word "proposed" with "tentatively observed" in the opening sentence. I do not think this is an improvement:

The phrase "tentatively observed" is very vague without further clarification. (Which the lede does not provide until the last paragraph.
It confuses the context of the first paragraphs. By saying "proposed", it is immediately clear that any properties mentioned are theoretical proposed properties, not properties that have been observed.

I strongly suggest going back to just saying "proposed" which is just as factual, and a lot less awkward and confusing.T R 07:42, 7 September 2012 (UTC)

I see your point about the properties, but there are a few problems-

the status of the particle is "tentatively observed" not "proposed" (see infobox).
It's confusing for the reader who 'knows' from the popular press that it has been discovered to come here and find it is only "proposed"
You have to read all the way to the 4th paragraph to find out that it has been tentatively observed and not just proposed.

We could also put something like this- "...Higgs particle is a proposed (and tentatively observed) elementary particle..." which while even more clumsy is accurate. Or maybe add a short 2nd sentence that says it has been tentatively observed. Bhny (talk) 09:09, 7 September 2012 (UTC)

There is no such thing as "the" status of the particle. So your first point is rather pointless. As for the second and third points, I think we can expected enough attention span of our reader to scan four paragraphs. (The third point also works against saying "tentatively observed" since readers have to wait that long to figure out what this weasel like phrase in the openning sentence means.

An alternative could just be omitting an adjective altogehter and just say. "The Higgs boson is an elementary particle in the Standard Model of particle physics." This is completely accurate , establishes the right context, and is considerably less awkward.T R 10:21, 7 September 2012 (UTC)

I support removing the adjective from the first sentence. If we do that, the last sentence of the first paragraph should certainly mention that a particle consistent with the Higgs boson has been detected at CERN. --Amble (talk) 14:58, 7 September 2012 (UTC)

I'm fine with what Amble and Timothy say- omit both and add a sentence at the end of the first paragraph saying "A particle consistent with the Higgs...." Bhny (talk) 17:11, 7 September 2012 (UTC)

We might also rework the first part of the second sentence to say that the Higgs was included in the standard model for theoretical reasons, and that it may now have been detected experimentally. The current "The Higgs boson's existence would have profound importance in particle physics" is not as informative as it could be. --Amble (talk) 17:42, 7 September 2012 (UTC)

This all sounds good. Do you want to do the edit? Bhny (talk) 18:41, 7 September 2012 (UTC)

I've made an attempt -- edit away. --Amble (talk) 23:18, 7 September 2012 (UTC)

Thanks, looks goodBhny (talk) 03:35, 8 September 2012 (UTC)

Possible different article split?

if the Higgs boson is confirmed, what would people think about splitting this article into Higgs field and boson, and a new article Search for the Higgs boson. The search itself is a very substantial topic, covering issues such as "why does it matter" and "what is the history" and a great amount of detail that really is not much to do with the particle itself. It might be easier to have an article on the particle/field with a summary style section on the search and its background. If it's not found then the particle is hypothetical and no need to split it really as the only "story" is the search. FT2 ^{(Talk | email)} 23:46, 17 July 2012 (UTC)

seems like a good idea to me. I would also suggest making a timeline of the search for the higgs boson. Amphicoelias (talk) 10:39, 18 July 2012 (UTC)

I don't think a split is essential at this time. Although in the long run an separate Search for the Higgs boson could be useful, especially if we want to include more detail on the search than we currently do. As for renaming this article to Higgs field and boson, I don't really see the need that badly. The current title "Higgs boson" can already refer to both.T R 10:51, 18 July 2012 (UTC)

I think that when the dust settles, the “Experimental search” and “Timeline of experimental evidence” sections ought to be culled according to the will-people-still-be-interested-in-this-in-ten-years criterion. But I'm undecided whether the excess material should be removed altogether or moved to a sub-article. A. di M. (talk) 22:43, 20 July 2012 (UTC)

The experimental search information should definitely stay somewhere. The Higgs went the longest from prediction to discovery of any particle (44 years, twice the top quark, easily more than the tau neutrino's 26 years). This difficulty has made it the last SM particle to be discovered and has become a significant part of its identity. I like the idea of moving details to a different article, though. Law of Entropy (talk) 05:55, 5 August 2012 (UTC)

Of course it will still be interesting after 10 years, from a science history perspective if nothing else. I think a separate article about the search is a good idea as well. 85.230.137.182 (talk) 21:09, 9 September 2012 (UTC)

I have gone ahead and started a separate article Search for the Higgs boson. I'll update it with some of the earlier history of the search as I have time. Once it has reached a decent state we may want to consider trimming the experimental search section here down.T R 20:55, 20 August 2012 (UTC)

"God particle"

I must take issue with the statement "In mainstream media it is often referred to as the 'God particle'". In fact, I have never seen it referred to as the "God particle" in any mainstream media. What I have often seen in the mainstream media are claims that other people call it the "God particle", using such phrases as "known as", "sometimes called", "so-called", etc., or scare quotes, or similar devices. As far as I can see, absolutely everybody mentions that other people call it that, but absolutely nobody actually does call it that. 86.151.119.57 (talk) 03:27, 14 September 2012 (UTC)

The are plenty of headlines that use the phrase "God particle" (with or without quotes.) That is referring to it as the "God particle". More importantly we have plenty of secondary sources that confirm this.T R 12:29, 14 September 2012 (UTC)

Cancel hypothezising and weasel words

I propose to cancel the following sentence:

"Proof of the Higgs field (by observing the associated particle) and evidence of its properties are 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.[12]"

It is useless to speculate about a discovery not validated yet. There are no facts, just appraisals of what a discovery might mean. The source is obviously not intended for factual infomation, but for justifying the efforts undertaken for the LHC. Uncommented citing of CERN's press releases violates the neutrality of wikipedia. — Preceding unsigned comment added by 84.151.158.174 (talk) 12:02, 16 September 2012 (UTC)

I don't see it as infringing WP:NPOV. The mathematics for the standard model points to certain effects, which would be confirmed to be correct by the confirmation of the particle. Silvrous ^Talk 12:10, 16 September 2012 (UTC)

Needs better account of significance in lede

I think this article could use a clearer and more prominent account for laypeople of what a Higgs boson is and why it matters. Something like the very nice note 3 currently in the first paragraph, but expanded and not hidden in a note.

Most laypeople I speak to (and not being a practicing physicist I suppose I am a layperson on this subject myself) seem to be under a vague impression that Higgs bosons have something to do with giving everything all of its mass, in a sense closely tied to gravity: I see people who imagine that Higgs bosons are either being exchanged between all particles all the time and somehow attracting them to each other, or that Higgs bosons are the elementary particle of mass and that all other massive particles have mass because they contain Higgs bosons (and they are then confused about how the Higgs boson has such a larger mass than the particles it "gives mass to" in this way).

The clearest explanation I have heard thus far (and please correct me if I get any of this wrong) proceeded along these lines:

First, it emphasized mass-energy equivalence, that to have mass is just to have energy, and that it is just this mass-energy which gravity acts on, and that this mass-energy can be in many forms or "come from" many places, including motion and interactions with the electromagnetic, weak, and strong nuclear fields.
Then it noted that even after we have accounted for the kinetic energy of all the particles that make up some hunk of matter, and of all the electronuclear forces binding those particles together, and are just considering a bunch of isolated elementary particles at rest, there is still some energy there we haven't accounted for yet; the original mass-energy of the matter in question, minus all the kinetic energy and all the binding energies, is still greater than zero; which raised the question of what form is that energy taking, or where does it "come from", if not motion or any of the known interactions?
Then it explained that the Higgs field is a proposed other field besides the known electronuclear ones, which all those elementary particles are interacting with, accounting for what that energy is bound up in, if not in moving the particles or interacting with the known fields.
Then it emphasized that a particle of any kind is just the minimum excitation of some field, and that we could therefore test for the existence of this proposed field by exciting it with enough energy in one place to manifest a particle, and that that particle is the Higgs boson; not that there are Higgs bosons anywhere in the matter with the unaccounted-for mass-energy, or that Higgs bosons are being exchanged between particles all the time; it's just something which could be created at high energies, if the Higgs field existed.
Lastly, it noted that it takes a lot of energy to excite the Higgs field, which is why we need huge supercolliders to run these experiments, and why the resulting Higgs bosons have a lot of energy and, equivalently, mass.

I think if we could get something along those lines, more concise and minus any technical errors I may have introduced, somewhere high up in the lede of this article, it would do a great service to a lot of lay people who have no idea what this Higgs thingy is. Thoughts? --Pfhorrest (talk) 02:26, 22 September 2012 (UTC)

A problem, I see with your proposal is that it spends a lot of words on explaining what the Higgs boson is not. That is not very appropriate for an encyclopedia. It is not generally up to us to correct misconception of readers. (It would be pretty hard to do so, while satisfying the base rules of wikipedia, most importantly WP:V) This is also the reason that note 3 is in a note and not the main text. (It is about what the Higgs is not) It is our task to explain-as clear as possible-what the Higgs.

Your last three points are already covered in the first paragraph. (Except for the arguementation for needing huge colliders, which is exactly accurate. The Higgs heavy, but not extremely so. It is lighter than the top quark, and not that much heavier than the W and Z. A much more important factor is that excitations of the Higgs field are very rare.)

Your second point is beating around the bush a lot. We simply observe that electrons (which are elementary particles) have mass (anybody with an oscilloscope can do so at home). There is no reason to contrive anachronistic for the existence of the Higgs. (Historically, the Higgs was proposed to explain why the gauge bosons of the weak interaction were massive (i.e. why their strength decayed exponentially).)T R 10:20, 22 September 2012 (UTC)

No evidence for lifetime yet

Since my edit was undone with no comment, I'd like to invite a discussion on the claimed lifetime. The value of 1.56 *10-22 is is just a theoretical inference how the particle should decay if it was a standard Higgs. There is no measurement confirming that range. Rather, the width of the signal (~8 GeV) corresponds to 10-25 s. Talking about "consistency" as abuse of language, since it does not include falsifyability. Evidence must be based on measurements which have error bars. — Preceding unsigned comment added by 84.151.156.239 (talk) 18:12, 18 September 2012 (UTC)

The observed decay crosssections in ATLAS and CMS are within a factor 2 of the SM predicted value. See [6]. (Assuming the particle is indeed the Higgs)T R 06:29, 19 September 2012 (UTC)

Moreover, since it is frequently remarked that the Higgs decays "very rapidly" it is informative to note just how rapid, even if it is "just" a theoretical estimate. There is note right there explaining the value. Simply, removing the entry as you did is not helpful to anybody. T R 09:01, 19 September 2012 (UTC)

I may agree in part. Still, the cross section is not a lifetime. Thus, something like "assumed" or "theoretical" should be added to the entry. — Preceding unsigned comment added by 84.151.158.123 (talk) 21:47, 19 September 2012 (UTC)

Crosssection, width, and lifetime are just slightly different ways of expressing the same physical quantity in this case. Do you also think we should add "theoretical" to all other properties in the infobox. The particle statistics, parity, spin, etc. have also not been measured.T R 22:00, 19 September 2012 (UTC)

Width and lifetime are related by Heisenbergs uncertainty relation, ok. But the relation to crossection relies on standard model assumptions, which still have to be tested. Moreover, the width visible in the diagrams [[7]] is about three orders of magnitude larger than a width that corresponds to the lifetime given here. In any case, you are assuming that the wikipedia reader has the background knowledge to understand that the value is theoretical. It might be clear that spin 0 is a theoretical requirement, but not 1.56*10-22. Adding "theorised" avoids misunderstandings and does no harm. — Preceding unsigned comment added by 84.151.192.17 (talk) 08:33, 22 September 2012 (UTC)

1)There is a note attached to the value that already says that this is the predicted value.

2)In this case decay width is not the same thing as the width of the observed mass. (The latter is widened because of uncertainties in the reconstruction of the center of mass energy.T R 09:46, 22 September 2012 (UTC)

Since you spelled it 1), I think we can agree that adding "predicted" clarifies.

Your remark 2) is interesting. Can you give a reference? — Preceding unsigned comment added by 84.151.192.17 (talk) 16:46, 22 September 2012 (UTC)

For the second point, see for example the ATLAS article on the Higgs results "The expected width of the reconstructed mass distribution is dominated by the experimental resolution for mH < 350 GeV, and by the natural width of the Higgs boson for higher masses (30 GeVat mH = 400 GeV)." (This is specifically about the 4 lepton channel.)T R 10:14, 24 September 2012 (UTC)

TR: first of all, I may be wrong but I've never heard practitioners of particle physics use the words "decay cross section". I suppose that the plots from the PDG review that you have in mind when you write "The observed decay crosssections in ATLAS and CMS are within a factor 2 of the SM predicted value" are those of fig.18. However, as the caption of that figure makes clear, the plots show the product of the cross section for the production of the Higgs boson times the branching ratio for each decay channel. Those plots contain no information on the total decay width of the Higgs boson (I mean: if all the partial decay widths were multiplied by the same factor, the branching ratios would stay the same, and so would the plots, but the total width would change). It seems to me that the anonymous editor above is correct when he/she stresses that the information on the width (which is a prediction of the Standard Model) should not be given the same standing as the information on the mass (which is measured). I will edit the note to clarify that the prediction is only valid in the Standard Model (in extensions of the SM the Higgs couplings to SM particles could be modified, and there could even be additional decay channels available). Cheers, Ptrslv72 (talk) 18:05, 22 September 2012 (UTC)

Indeed "decay cross section" is poor use of language. (Nonetheless, the data is not compatible with the 10 s meanlife originally claimed by the IP)T R 10:14, 24 September 2012 (UTC)

On this you are absolutely right: for low values of the Higgs mass the width in the mass distribution is determined by the resolution of the detector. Besides, if the Higgs boson had a lifetime of 10s (!) it would leave the detector well before decaying... (also note that the plot linked by the anonymous editor shows 95% CL exclusion bounds on the Higgs production cross section as a function of the mass - the width of the peak visible there has nothing to do with either the Higgs decay width or the experimental resolution). Cheers, Ptrslv72 (talk) 15:42, 24 September 2012 (UTC)

One more thing: the infobox says that in SUSY extensions of the SM there are five or more "types" of Higgs bosons. Now, the Higgs sector of the MSSM contains two SU(2) doublets, and after the breaking of the electroweak symmetry the physical states are indeed five: two neutral scalars, one neutral pseudoscalar and two charged scalars. I see some contradiction here with the fact that the infobox defines the Higgs boson as a particle with zero electric charge. Perhaps we should remove the entry "Types" from the infobox, and make clear that all the information there refers to the Higgs boson of the SM. Cheers, Ptrslv72 (talk) 18:26, 22 September 2012 (UTC)

This seems reasonable to me. For the moment this article is somewhat caught in an uncomfortable split between theory and observations of a particle that may or may not be (but most likely is) the Higgs boson. For the moment, talking about all the excitations of the Higgs fields in the MSSM as "Higgs bosons" just adds to the confusion, and should probably be limited to one section. (Although in many things said about the theoretical Higgs boson apply just as well to the lightest neutral Higgs in the MSSM as they do to the Higgs in the SM.T R 10:14, 24 September 2012 (UTC)

Probabilities associated with "sigmas" should be removed.

The article makes claims that certain values of sigma (eg 5 sigma) correspond to certain probabilities that the experiment is wrong (less than one in a million). These should be removed. They are based on the assumption that the "errors" are Gaussian distributed, and they certainly are not. The distribution is unknown (especially for the systematic errors but also for the statistical) and depend critially on data cuts etc. Remember the number of sigma quoted for the Opera "faster than light" result. Does or did anyone ever believe that this meant that the chances that that experiment was wrong was 1 part in 10^20 or something? It is simply nonesense to go from some number of sigmas to a probability as if the distribution were Gaussian. Experimentally, if one looks at all experiments which quoted a 5 sigma result and asked how many of them were ultimately shown to be wrong, the figure would probably be closer to 10% rather than one in a million. — Preceding unsigned comment added by 212.186.62.238 (talk) 13:46, 22 September 2012 (UTC)

Actually, I don't think there is any assumption about Gaussianity of the distribution. In this type of context, the statistical analysis of the data outputs probabilities and 5 sigma significance simply means that the chance of finding said result based on the background hypothesis is smaller than 1 in a million. (i.e. sigma does not necessarily represent a real standard deviation of the distribution, and 5 sigma is not necessarily 5 times 1 sigma).

Nonetheless, the languages used when saying this in the article can be sharpend up a little. Since it is not the chance that the result is wrong, it is the chance that the result is symply a stastically anomaly, which does not include the chance that there is some unknown source of systematic error. (As turned out to be the case in the OPERA result.)T R 09:55, 24 September 2012 (UTC)

I do not think they should be removed (they are not nonsense, rather they are easier to understand than 'sigma' which most people do not understand) but sharpening up the language to avoid misunderstandings is a good idea. 85.230.137.182 (talk) 22:24, 24 September 2012 (UTC)

Named after Higgs since when?

Since when has the Higgs boson been called after Higgs? --149.217.1.11 (talk) 09:02, 24 September 2012 (UTC)

This is one of these things that has grown organically, and the stories differ. So, it is difficult to peg a date. But basically since the the early seventies.T R 09:44, 24 September 2012 (UTC)

Mass in summary table

The text of the article nicely and carefully points out that the discovery this summer at the LHC experiments is not of a the higgs boson, but rather a new boson (spin 0 or 2) with a mass of approximately 125 GeV and properties _so far_ consistent with the higgs boson. The PDG has so far been careful (in their PDGLive version) not to give a mass from the summer results on the page for the higgs boson. I don't think Wikipedia should jump the gun. The listing of the new findings in the text is fine; but in the summary table, the proven mass limits should be given. --Certain (talk) 15:49, 1 October 2012 (UTC)

I agree to some degree.

On the other hand, if I remember correctly, the exclusion ranges reported in the same summer results are close to the same numbers. So, if the SM Higgs exists its mass should be in this range (approximately). The PDG summary page for the Higgs boson is completely empty (because there has been no official discovery). So, by the same argument all our other fields on properties should be left empty as well. This is neither informative or helpful. The key difference is that Wikipedia, in contrast to the PDG, also reports on theoretically (or otherwise) expected phenomenon and properties.

I think the thing to do here is to clarify that these numbers assume the observed particle is the Higgs.T R 16:07, 1 October 2012 (UTC)

Even the summary table states clearly (twice) that the observed particle is only "consistent with" the SM Higgs boson. I think it's already rather clear that the numbers quoted for the mass refer to the particle "tentatively" identified with the Higgs. However, this can be mentioned more explicitly if you want. Cheers, Ptrslv72 (talk) 16:43, 1 October 2012 (UTC)

The PDG entry for the Higgs is not empty. It lists the mass as confined to 115.5--127, basically. The other fields in the summary table (charges and spin) can be taken as listing the properties of the theorized boson, but the mass is different and purports to be a measured mass of an identified Higgs boson. There is no theoretical prediction of the Higgs mass. The "tentative" disclaimers are in the status and discovery info, I don't see it as explicitly stating that the mass is of the tentatively discovered Higgs. If one really wants Wikipedia to be an encyclopedia, one should have standards for exactness. Here clearly ease is being favored over correctness. --138.246.2.254 (talk) 11:58, 4 October 2012 (UTC)

Width vs Lifetime

Why is the mean lifetime reported instead of the width? The width is the value calculated, the value that will be measured. Why list the lifetime and then note that is obtained by converting the width, instead of just listing the width. Particle physicists care about widths, not mean lifetimes (for such promptly decaying particles, at least). — Preceding unsigned comment added by 88.64.0.136 (talk) 00:23, 12 October 2012 (UTC)

Because particle physicists are not the target audience of this article. To the general audience, mean life is a quantity that is much more easily understood than decay width.T R 06:39, 12 October 2012 (UTC)

However the lifetime is nearly meaningless, and is not the way that this quality of such a particle is expressed. The target audience of this article is someone who wants accurate information about the Higgs boson. Presenting the information in an uncustomary format alien to the subject, is against the idea of an encyclopedia. The width should be listed, and a link to the page explaining the width of a particle provided. — Preceding unsigned comment added by 88.64.0.136 (talk) 00:36, 15 October 2012 (UTC)

a) Mean life and decay width contain exactly the same information so the one cannot be more meaningless than the other.

b) Mean life is not alien to high energy particle physics at all. (See for example the PDG entry for the muon)

c) To a lay reader, the decay width of 4 MeV is a uninformative number (he/she wouldn't if it is large or small), while a meanlife of 10^-22 s immediately tells any reader that this is a highly unstable particle.T R 07:14, 15 October 2012 (UTC)

I agree with TR, lifetime is physically equivalent to total decay width but more accessible to the lay reader. Cheers, Ptrslv72 (talk) 11:03, 16 October 2012 (UTC)

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)

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)

You might want to look at [8].T R 07:08, 29 October 2012 (UTC)

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 (talk • contribs) 01:56, 14 November 2012 (UTC)

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.T R 07:27, 14 November 2012 (UTC)