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Have Scientists Found Two Different Higgs Bosons? (scientificamerican.com)
63 points by ColinWright on Dec 14, 2012 | hide | past | favorite | 47 comments


The most important lesson I learned in graduate school came from a scientist at Los Alamos who told me "three sigma effects happen in physics much more often than they should"


You think that's bad?

How about in finance, where the CFO of Goldman Sachs bemoaned that they had "25-sigma events, several days in a row" during the financial crisis.

http://lukenotricks.blogspot.com/2010/03/fabled-25-sigma-eve...


Surely at the claimed 25-sigma point, the problem is more with our ability to measure than the probability itself? Claims about the space shuttle's reliability come to mind.

Am I the only one who feels that a claim of probability on this level is basically religion on one level or another?


The problem is that the model was fantastically far off from reality. (For whatever reason - incompetence, bad inputs, willful deception, religion - doesn't matter for this discussion.)

I could construct a prediction that the high air temperature in New York tomorrow will be 80 degrees Celsius with a standard deviation of 3 degrees. Then when the observed value is actually 5 degrees, that's 25 standard deviations off from my "prediction". But it doesn't mean that the observed event was actually a 1-in-billions occurrence, that New York experienced an astronomically unlikely cold snap. It means my prediction was unrealistic and wrong, that it didn't model reality.


The math works, based on the model. The model works based on the human guessing what the model should be. The real problem is that '25-sigma' events in the model are completely overshadowed by the not-all-that-small chance that the model is wrong. So talking about 25-sigma events as if it was something you could manage and control, when they are so far below the noise level of human error (or lack of information/understanding) is nonsense. It tells you something, but if you throw away the context, it will happily lie to you.


Computers can measure to arbitrary precision, so that's not the problem, and if you have good reason to think that you have 25 sigmas worth of evidence, that's still very different from a religious belief which needs infinitely more evidence to justify, or a religious belief of having unshakable meta-belief in the probabilistic model such that you never update it when it's wrong. The problem is really just a bad model, or (as with Challenger) ignoring the computer/engineer/model completely. Probability is in the mind; "events" happen, not "25-sigma events"; if your model is predicting a very low chance of something that happens much more than warranted, your model is very wrong. Is it so wrong it needs to be cast out entirely? Possibly. I'm more interested in how it gets updated when it's wrong.


Certainly. When reality disagrees with your theory you don't blame reality, you blame your theory. The idea that there would be yet another housing bubble which popped and that this might cause a massive number of defaults from "sub-prime" lenders is not exactly fucking rocket science, it should have been on the mind of anyone and everyone investing in that business. That's not a 25-sigma event, that's a 0-sigma event, it's predictable and inevitable. By making it seem like the inevitable was impossible these charlatans transformed an ordinary housing bubble into an existential crisis for the world financial industry. It's a shame more of them aren't in jail.


Of course everyone is freshly aware of the neutrino fiasco, so this anomaly will probably be handled with extra skepticism and timidity. Without more data we can only make conjectures based on Occam's razor, etc.


The neutrino fiasco was very unfortunate since by all accounts the scientists involved went public with some seriously stressed skepticism. That heads rolled because outsiders ignored the skepticism is rather distressing.


It's unfortunate and leads to secrecy regarding potential discoveries instead of keeping the public up to date with what's going on.


Heads rolled?! I remember the neutrino story being handled with complete professionalism at the time. I wasn't aware there'd been any new developments. Do you have a link?



Much appreciated, thanks. That's absolutely tragic, and a failure of the scientific community and media at large. The media for precipitating it, and the scientific community for letting it happen.


Several people were pseudo-fired/resigned as I recall.


That sort of thing perverts the way that science is done. There's an increasing zeitgeist that "science" is done by publishing papers which present evidence which confirm existing theories. This has led to a lot of unpublished papers and a growing problem of "fudging results". We need science to be an open and honest discussion where experimental results can be presented without the researchers being at risk of opprobrium merely because the particular evidence doesn't conform to the status quo.


I (with minimal physics background, I admit) would bet on systematic error. We're seeing one mass from one decay path, and a _very slightly different_ mass from a different decay path. The best explanation seems to _me_ to be that, for one or both of the decay paths, there's a problem in how we're computing the Higgs mass.


This is how I lean too. A few percent in a mass measurement is a pretty small systematic error and could easily come from something that has been overlooked or miscalibrated. There are a tens and hundreds of calibration and corrections that go into these detectors and analyses and it's all too easy to miss something.

What really makes me convinced it is an experimental error is that CMS does not see the same mass discrepancy. If both independent experiments saw the same discrepancy then this would truly be really interesting new physics.

Disclaimer: I am on ATLAS myself, though not associated with the Higgs groups. I can only comment on public results due to much information being confidential.


BTW 3GeV is not "very slightly different". It's the mass of 3 protons, which for subatomic particles is a lot.


Wikipedia says this is possible with a more complex theory. Are we going with the simplest theory due to Occam's razor?

The Minimal Standard Model as described above contains the simplest possible model for the Higgs mechanism with just one Higgs field. However, it also is possible to have an extended Higgs sector with additional doublets or triplets. The non-minimal Higgs sector favoured by theory are the two-Higgs-doublet models (2HDM), which predict the existence of a quintet of scalar particles: two CP-even neutral Higgs bosons h0 and H0, a CP-odd neutral Higgs boson A0, and two charged Higgs particles H±.

https://en.wikipedia.org/wiki/Higgs_boson#Alternative_models


The W and Z bosons are basically the same, except one is charged and the other neutral. And due to that they have different masses.

So it's certainly possible the same thing could be happening here.


The W and Z particles are a little more different. The W+- particles only interact with L-hilarity particles. The Z particle "prefers" the L particles, but also interacts with the R particles.

It's more complicated. There is a W^0 particle that is the neutral equivalent of the W^+ and W^- particles, all of them have the same mass. There is another particle called A, that is like a photon with mass (but it "sees" the hypercharge of the particles, not the charge)

Combining the W^0 and A particles, it's possible to get two new particles the Z^0 and the photon. In this combination the Z^0 has all the mass and the photon has no mass. It's more easy to understand some experiments using the Z^0 and the photon, so to make some explanations more clear it's better to use them instead of the W^0 and the A.

IIRC, for low energy experiments it'd better to use Z^0 and photons, and for high energy experiments it's better to use W^0 and A.


You are mixing conjectures from string theory and other theories with known physics.

I can found no info on the W^0 or the A, R and L are a type of conjectured parity, not actual particles, and hypercharge is an obsolete concept.

You should be more careful about where you learn physics, and very very careful to distinguish known physics, or theories with evidence from conjectures and ideas. Both are necessary - but don't mix them up.


What?! I'm taking only about particle physic (I don't know almost anything about string theory).

The W^+,W^0 and W^- are a weak-isospin triplet of bosons that are the carriers of the "real" weak force, assuming that the SU(2)_L symmetry holds for the weak-isospin doublets (electron_L-neutrilo_L), ...,(up_quark_L, down'_quark_L),... (Sometimes the weak-isospin triplet is written as W_0,W_1 and W_2, using another base.)

I rememberd incorrectly the name of of the particles "A". Sorry. The correct name is B^0. This is the of the field associated to the weak hypercharge with the U(1) symmetry. I know hat the old hypercharge is not more a very useful concept, but I was trying to simplify a little the notation and I dropped the weak part.

All of this is the electroweak force theory (unification of the electromagnetic force and the weak force). http://en.wikipedia.org/wiki/Electroweak_interaction

In this theory each fermions can be classified as L or R chirality (it's a "property" of the particles, not an independent thing) (the mass of the particles makes this a little more complicated). The "real" weak" force only interacts with the L version of the particles.

This has many experimental results, for example the ratio between the mass of the Z^0 and the W^+- particle is indirectly related to the ratio between the coupling of the Z^0 and the L and R electrons.

All of this id proved beyond doubt, but it assumes that the particles doesn't have mass. They have an apparent mass created by the Higgs mechanisms (or something equivalent), so there must be Higgs bosons out there. So the only missing part is to prove the existence of the Higgs bosons, and it's almost done (5-sigmas next year?).


Other than monotheistic bias, why should multiple species of god particles be surprising?

Perhaps the first should be called "Odin" and the second "Loki."


My joke sensors might be burnt out, but...

http://en.wikipedia.org/wiki/Standard_Model

Look at the 'periodic table' on the right. Everything has a place, and makes sense. The quarks and leptons have their pattens with increasing mass ect, and there is one Gauge boson for each basic force of nature. If there was a second Z boson... where would you put it?


Where does one put deuterium and tritium or carbon 14?

The model ain't the reality.

The standard model has six quarks, up from the three initially proposed.

In fairness, discarding data which does not fit the model has not been without it's practitioners. However, the method's history is somewhat less than distinguished.

http://en.wikipedia.org/wiki/Quark#History


You put deuterium and carbon 14 'on top' of their respective elements on the periodic table. (or at least in my mental model)

> In fairness, discarding data which does not fit the model has not been without it's practitioners.

I'm not trying to say we should discard data, I am pointing out that we would need to discard our model. (or at least a part of it) And discarding a model that has been around for so long is always surprising. (or at least to some people)


Fun fact: nobody knows why there are 3 generations and two types of quarks and leptons, or why the family relationships of quarks seems to mirror that of leptons.


I'm looking at that table and I can't see where the Higgs boson would go either. Where would we put the Higgs?


Near the W and Z, and there seems to be a missing particle near the photon and gluon - probably the graviton.


Why stop at 2, for all we know others are created by the impact in another universe(s). We don't really know. But sure is fun and the whole higgs boson mystery is still very much alive.

I don't believe we will truely understand the higgs boson until we fully understand gravity and more so explain why it is weaker than it should be.



If anyone is wondering the answer is: No.

http://en.wikipedia.org/wiki/Betteridges_law_of_headlines


That's about TechCrunch articles that talk about Apple. It's not about real science and makes no sense in this context.


"Have scientists found the source of immortality?" "Have scientists invented flying shoes?" Just because it's a scientific article does not mean it's any less applicable.

The headline could easily have been "New data shows possibility of" or "New theory suggests" or countless others.


Your examples are ridiculous. The answer to the question is not "No". The question has no answer right now other than "maybe, we'll see". Not everything is so black and white.

Yes, there are other possibilities for the headline. No, the silly law about internet headlines does not extend to articles with real information about real science where real questions are posed and currently unanswered.


If the answer is "We don't know", then the article should not be posting headlines as questions they don't have an answer too. Unless they are just fishing for traffic.


The website linked here in a Scientific American blog. Their job description is probably two words: "ask questions". Questions are extremely important.

> If the answer is "We don't know", then the article should not be posting headlines as questions they don't have an answer too.

Am I feeding a troll? This is silly. Publicly asking questions that you don't have an answer to is perhaps the single most important feat humanity has ever achieved.

Just calm down about the question, yeah? It's important, and it's not "fishing for traffic". It's a real, serious question.


> Am I feeding a troll?

You just disproved Betteridge's law


You can do that far better by applying it to itself ("Can any headline which ends in a question mark be answered by the word no?") or with a question requiring a non-yes/no answer ("How many Higgs bosons has ATLAS really found?").


> "Have scientists found the source of immortality?" "Have scientists invented flying shoes?"

If the scientists in question did not have evidence to suggest those things, then those articles would not be scientific articles.

If they did, then citing Betterridge's Law would be misplaced.


It's an interesting law, I know. But it's usually applied to contentless news articles that raise a question when they have nothing to talk about.

This article is not that way, it has actual info.


So the answer isn't no? They did find two of the Higgs Bosons?


There exists a third possible answer: We don't know yet.


Which is probably the real answer and should be treated as such. I can't stand these "Did science just discover that Jesus was out to lunch with Jay Z?!?!" NO, it didn't.

I don't know if I'm just pissed off today because of the whole CT thing, or because I see more and more mass media outlets posting nonsense about science, but if you have to ask "did xyz discover blah blah blah" the answer is probably no. It's misleading, and poor form to say stuff like that.

Does posting on HN cause BRAIN CANCER?!?!?!? What you don't know about posting on the internet could kill you and your family, twice.....more after a new episode of Modern Family! [/end anger]


Don't know why people are downvoting you. The best fit value for the cmbined channels is in the 95% confidence level for both single channels, so I belive we can argue that Betteridges law is correct (at 95% CL).


People are probably downvoting him because they are sick of hearing about that stupid law on HN. If you think the answer is "no", say why you think it is "no". There is interesting discussion to be had there.

Saying the answer is "no" because the headline ended in a '?' adds nothing to the conversation.




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