Higgs Boson Detected? 52
Travis McGee writes "A scientist says one of the most sought after particles in physics - the Higgs boson - may have been found, but the evidence is still relatively weak. The Higgs boson explains why all other particles have mass and is fundamental to a complete understanding of matter. The report was published in Nature magazine and the BBC has an article." The last time the elusive particle was in the news was 2001.
The boson kludge (Score:2, Interesting)
Reminds me of the "dark energy" idea: "Well, we can only find 1/3 of the matter that we know should exist, so the rest is.. well, it's just the dark energy that we can't detect!"
Re:The boson kludge (Score:5, Insightful)
In that December 2001 article, we have statements like this: "Their conclusion is that there was nothing in the data at all to suggest the Higgs is out there - certainly not at energy masses of up to 115 Gigaelectronvolts (GeV), way past the level of 80 GeV where the boson was expected to show itself."
Contrast with March 2004: "Dr Renton cites indirect evidence taken from observations of the behaviour of other particles in colliders that agrees with the figure of 115 gigaelectronvolts for the mass of the Higgs boson."
The great thing, though, is how science done right is self-correcting. As soon as this boson was declared unlikely, researchers apparently began to attempt to prove that it did exist. Now that there's a theory that it exists, more researchers will begin trying to prove them wrong. Eventually, with all the facts out in the open, science will discover something approaching the ideal theory, which will likely be something unexpected.
It's like Microsoft vs. open source... find a bug in Windows, and it takes 9 months to patch it. Find a bug in Linux, and someone will patch it the same day...
(Obligatory disclaimer: I'm no physicist, and talk of "energy masses" and "gigaelectronvolts" makes my head spin. May as well be talking about Vitamegavegamin.)
Re:The boson kludge (Score:4, Funny)
The correct spelling is Vitameatavegemin.
Vitameatavegemin contains vitamins, meat, vegetables and minerals. That's Vita-Meata-Vegemin.
Drumroll please, as we find out how old the moderators are.
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A certain old sitcom :) (Score:1)
Unlikely, given (a) the near-constant re-run of "I Love Lucy;" and (b) the presence of a banner on the side of an office building in Hollywood, which is essentially a photorealistic rendition of the Vitameatavegemin episode.
Re:The boson kludge (Score:5, Informative)
In 1930 or so, Wolfgang Pauli noticed that in all interactions, this strange combination of variables (what we now call spin) stayed constant through those interactions. But he couldn't fully explain beta-decay, or when the nucleus of an atom spits out an electron ... this 'spin' wasn't conserved.
So, Pauli invents an incredible particle: it has little or no mass, hardly ever interacts with anything, but carries spin. It helped his equations balance.
Naturally, most of the scientific world scoffed at his idea at the time: it implied that hundreds of trillions of these things would be flying through space every second. AND they were undetectable?!? Quite a stretch.
But history bore him out, and neutrinos exist. You can see a history of the neutrino here [ohio-state.edu], for more info, including current discrepancies with our understanding of neutrinos.
Quantum mechanics kinda developed the same way ... crazy math with weird conclusions went AHEAD of experiments, and those experiments bore out the math 5 or 10 years later. I believe the same approach is being taken for the matter in the universe (WMAP predicitons), as well as the higgs boson.
Just my 0.02 euro.
Re:The boson kludge (Score:2)
The only way to explain that was to have a third particle, the neutrino, produced by the decay. It would take away var
Re:The boson kludge (Score:2)
That is, there are some things that are true that cannot be proven (or here predicted) by math.
And so I am left to wonder whether this mathematical prediction approach can ever give us the whole picture...
Re:The boson kludge (Score:1)
I'm by far no math guru, but the way I've understood it, Godel's proof showed that within an axiomatic system there are true statements that you cannot prove. That doesn't change the fact that they may be true.
http://www.sm.luth.se/~torkel/eget/godel.html [sm.luth.se] looks like a nice place to review some Godel.
Re:The boson kludge (Score:5, Insightful)
So, the standard model defines 16 particles. But if there are only those 16, then none of them have mass, so there must be another one, that magically provides mass for the others. Weird. You can't make this stuff up, folks... err... oh, wait.
Nice try. Apart from the fact that the article's description of the role of the Higgs in generating masses isn't quite correct, there's your implication that this is some what frivolous. Well, if you evaluate scientific theories by the accuracy of their predictions, an argument can be made that the standard model of elementary particle physics is the most successful scientific theory of all time -- ranging from making correct predictions of electrodynamic phenomena out to absolutely absurdly large numbers of significant digits, to making predictions about the numbers of certain types of particles that will exist ("there will be one more light neutrino species, but no more after that") -- subsequently confirmed.
There are a lot of things you can fairly criticize particle physicists about; but suggesting that the standard model is removed from reality isn't one of them.
Reminds me of the "dark energy" idea: "Well, we can only find 1/3 of the matter that we know should exist, so the rest is.. well, it's just the dark energy that we can't detect!"
Like many people, you've got "dark matter" and "dark energy" confused (I personally hate the "dark energy" term, and wish Michael Turner (I think it was him) hadn't coined it; but we're stuck with it now). And while either of them may someday turn out to have been a wrong turn in the history of cosmology, neither is an unfounded concept.
Re:The boson kludge (Score:4, Insightful)
I'd love to agree with you, but the Standard Model's Higgs mechanism has absolutely no authority to avoid the term "frivolous." In a lot of ways, it is.
The Higgs mechanism is done in the simplest way possible to generate masses - it uses a scalar field, which is the simplest field you can use, and, curiously, of which there are no other examples in nature - leptons and quarks are spinors (fermions of spin-1/2), photons/gluons are vectors, and even gravitons, if they exist, would probably be tensors.
There's no reason to desparately cling to the Higgs mechanism, other than we have no other way of generating mass that theorists 'like'. And, to be perfectly honest, this 'detection' does raise eyebrows - it's at the edge of LEP's detection, and it's only a 3 sigma (or so) detection. Now, that's not saying that Nature can't have been cruel to us and put the Higgs right at the edge of LEP's detection range, sure - worse things have happened. But it's a little suspicious.
Also, the Higgs "boson" has predicted nothing - anything that does symmetry breaking in a similar way would predict exactly the same thing.
(Sorry - I hate the fervent adherence to the Higgs, especially when we've looked, looked, and keep having to shove the mass up 'just a little higher' to the next accelerator range. I also hate the fact that no one else thinks that maybe a fundamental scalar just isn't possible for some subtle reason we don't understand. This would allow much more complicated Higgs interactions which people have typically ignored based on simplicity arguments. People said "if LEP doesn't find the Higgs..." and now people are saying "if LHC doesn't find the Higgs..." - what's next?)
("there will be one more light neutrino species, but no more after that")
To nitpick, the "N=3" discovery is only valid in the energy range of interest. You have to generate the lepton partner as well, so while the neutrino species could still be light, the lepton partner could be ungodly heavy, and thus outside of the detection field.
It would have to have odd mixing angles, sure, but a fourth family isn't out of the question.
Re:The boson kludge (Score:5, Informative)
That's not quite fair ... as a low energy effective theory, the SM is spectacularly successful, and is not in demonstrable conflict with any experiment to date. This success is underpinned by a reliance on a Higgs-like mechanism. The SM one-doublet model may be economical and incomplete, but because the rest of the model holds up so well to tests, it is hard to see how the correct model wouldn't necessarily have a SM Higgs-like excitation in the low energy limit. Which isn't to say that it will be exactly like the SM Higgs, just that it won't look too different at low energy, or we already would have seen its impact in precision eletroweak measurements, for instance.
it uses a scalar field ... of which there are no other examples in nature
That isn't quite a fair argument, of course ... we have no experimentally confirmed examples of fundamental tensor fields, either, but most of us think gravitons exist :-)
And there isn't a compelling reason to expect light scalar fields, in fact quite the opposite. You are no doubt aware of the quadratic renormalization of scalar masses, whereby their masses are "pulled up" by any interactions they have. So you probably wouldn't expect massless or even light scalars, unless they don't have any interactions (in which case we wouldn't know about them). In SUSY, for instance, you would generically expect scalars to end up with masses near the SUSY breaking scale, something like a few hundred GeV ... well, except for the lightest Higgs, which has to have a mass somewhere in the neighborhood of 100-200 GeV to stabilize the electroweak symmetry breaking transition.
This would allow much more complicated Higgs interactions...
There are plenty of examples of non-fundamental scalar Higgs mechanisms, and even mechanisms that employ fundamental scalars that must be heavier than we've seen. SUSY, dynamical symmetry breaking, extra-dimensions, deconstruction, etc. But they all have their own challenges, usually conflict with existing data. That, of course, is the cardinal sin in physics. No matter how lovely your theory, Nature is always right, and if you don't agree with Her, you lose. :-)
To nitpick, the "N=3" discovery is only valid in the energy range of interest.
To pick nits with your nitpick (how's that for a turn of phrase?), N=3 is the statement that there are no more SM like light neutrinoes, and hence there are only three generations of SM fermions. The precision Z boson line shapes from the four LEP experiments provide exceedingly severe constraints on weakly interacting fermions, and those line shapes are inconsistent with the presence of fermions that we haven't yet seen which are lighter than half the Z mass. In particular, the invisible line shape is consistent with more than 2.something and fewer than 3.somethingelse neutrinos, and since we already know that there are at least three, we conclude that there are only three.
It would have to have odd mixing angles, sure, but a fourth family isn't out of the question.
It would have to have VERY odd interactions with the SM gauge fields, to the point where it wouldn't look much at all like the rest of the SM families. There just isn't room in the precision electroweak data for much else that looks anything like the known SM fermions. In this sense, you probably wouldn't call this "fourth family" a family at all. Additionally, SM like interactions with heavy neutrinos are probably ruled out by cosmological over-closure arguments and astrophysical stellar models, although those arguments are somewhat more tentative.
There might, of course, be non-standard model like heav
Re:The boson kludge (Score:3, Informative)
Is that true? I didn't think the precision electroweak stuff depended too much on the pure Higgs interactions, but just on the symmetry-broken 'residual interactions' - i.e. the ones that gave the particles mass. I always find it hard to tell, though, as most books completely gloss over the Higgs physi
Re:The boson kludge (Score:1)
I hate to get involved in a debate which is clearly out of my league, but here I can relate.
You're taking the approach that any anti-science person can make: "Since you haven't found it yet, it doesn't exist. Stop playing with bugs, and come over here to peel potatos."
Not that I'm accusing you of being anti-science. (Far from it! You seem to have ideas worth exploring.)
Re:The boson kludge (Score:2)
Any theory that can arbitrarily fit data based on an adjustable parameter at some point has to be discarded simply on simplicity grounds. There are many examples like this - Brans-Dicke theory is a good example - it's characterized by basically one parameter, which in the limit of it going to infinity becomes general relativity. The problem with this is that if we say "well, maybe the parameter's just a bit higher..." we'd be here till the end of time tryin
That's all well and good, but (Score:1, Offtopic)
Re:The boson kludge (Score:2)
Re:The boson kludge (Score:1)
For example, ancient astronomers impressed people for centuries with their ability to predict eclipses using the ptolemeic model. Everytime they got an unexpected result they just added a patch. B
Re:The boson kludge (Score:5, Interesting)
First of all, "dark energy" has nothing to do with the missing mass problem. You meant to say "dark matter." Dark energy is another term for the cosmological constant, a parameter tied to the observed acceleration of the universe. There are completely independent measurements that require this parameter, including supernova acceleration studies and incredibly precise cosmic microwave background measurements.
Regarding dark matter, you seriously trivialize the situation. It's not a case of astronomers being unable to find the matter, like it's a lost set of keys. We see that galaxies and clusters of galaxies experience more gravitation attraction than they should, based on the visible mass. Hence "dark matter." But it's not just that we can't see it; big bang nucleosynthesis tells us that only a small fraction of the matter in the universe is baryonic. Baryons are the normal particles that "stuff" is made of, like you, me, stars, dust, and gas. That means that the missing mass is not simply something we're not seeing (because it doesn't glow, for example), but is something utterly different.
We're not missing mass because we're not good at finding stars, or dust, or whatever. We're missing it because it's something completely, fundamentally different from all of that stuff.
Re:The boson kludge (Score:2, Interesting)
Why is this completely unrelated to dark matter, though? What are the observat
Re:The boson kludge (Score:5, Informative)
Again, these are two completely separate concepts. One makes things fly apart, the other helps keep things together.
Since the 1930's, it has been known [berkeley.edu] that stars in galaxies orbit the center of the galaxy more quickly than they should, based on the visible matter. This requires extra "dark matter" to provide enough gravitational force to result in the observed rotational speed.Re:The boson kludge (Score:3, Interesting)
You are contradicting yourself. It is a case of astronomers being unable to find the matter.
Re:The boson kludge (Score:3, Interesting)
No, I'm not contradicting myself. I was indicating that it's not simply being able to find something "normal," like a lost set of keys. The stuff we can't find is fundamentally different from normal "stuff."
Not true. The theoretical predictions of BBN, from particle physics, are in good agreement with observations of deuterium abu
Speaking of dark energy (Score:3, Interesting)
Re:The boson kludge (Score:5, Insightful)
MOD PARENT UP (Score:2)
Re:The boson kludge (Score:1)
I suppose my post came across as a a rather flip criticism of particle physics, but in fact it was meant as a commentary on the article itself. I realize that it was intended to explain the concept for laymen (such as myself), but often these articles obscure more than they explain.
I hope no as
Re:The boson kludge (Score:1)
It's worth bearing in mind that one might have said the same sort of thing back when epicycles were the state of the art way to describe planetary orbits: "we didn't ask for all these epicycles to show up. We're just trying to figure out what we're seeing in nature."
Re:The boson kludge (Score:1)
No.. it's falls naturally out of the electron-weak theory.
The electroweak theory unifies the electromagentic field and the weak theory. The original theory implied a massless W, Z and photon. This theory however is clearly incorrect as the mass of the W and Z particles are over 80 times larger that of the proton.
This break down of the symmetry between the electromagnetic and weak forces below energies of 100GeV coupled with the fact that W and Z are so heavy implies there is some mechanism beyond the
MOD PARENT UP! (Score:1)
Very insiteful!
Different Name (Score:3, Funny)
Re:Different Name (Score:4, Funny)
Actually I prefer weak grin bozon.
Well, OK, this particle is already named in the "Theory of Extra Special Relativity":
We start from the foundation of the dopeler effect: Stupid ideas that come at you rapidly seem smarter than they actually are.
Through our observations of individuals exposed to prolonged dopeler-shifted emanations, we can see that emission of dumb ideas tends to attract other dumb ideas, which in turn leads to a chain reaction of idiocy. All minds in the vicinity of high energy dolt fields are warped, consequently all conversations seem to take an infinitely long time.
Experimental evidence suggests that there is a limit to the density of weak grin bozon sources that any given region of space may sustain. Once this limit is passed, all thought in the region collapses in on itself to become a Quantum Imbecilic Singularity, from which no good idea may escape. QIS formations may be detected by searching for accretion disks of broken dreams, and massive jets of anticluons coming from a vector perpendicular to the back end of the accretion disk.
Nothing new here.... (Score:5, Insightful)
- less than 3 sigma deviation from background: ignored
- 3-5 sigma deviation: evidence for
- 5+ sigma deviation: discovery
At 9% chance he's wrong, it sounds like he's at around 2 sigma. Which is pretty much ignored by the scientific community. Which is why the LEP was shut down to make way for the LHC.Re:Nothing new here.... (Score:2)
Seriously, I'd be very, very suprised everything rounded out neatly into existing textbook formulas. Witness the new D-vitamin interaction they recently discovered that upset the neat tables in textbooks like that.
The Lexx prediction (Score:1)
Not News (Score:5, Informative)
Posted by: Throwaway
On: Wed March, 10 2004 @ 20:33 GMT
This is old news, folks. Just signed up to tell you that BBC is recycling news stories to fill column-inches. I'm sitting on site a few hundred yards from the beamline. LEP shut down a couple of years ago, and there's been no real news since then.
My group works exclusively on Higgs searches and more or less leads the effort here on experimental analysis in that direction. Sorry.
9% is nowhere near close enough. And the BBC story is wrong - Higgs doesn't really explain where the mass of all particles comes from. And "the God particle" is a stupid marketing ploy for funding agencies. There's a lot more to go. Higgs has been the fundamental theory hole, not pivot. If we get one, it'll round things off nicely.
Stay tuned for 2007-2008 (9?)
but the evidence is still relatively weak. (Score:3, Funny)
Was the pun intentional?
Re:but the evidence is still relatively weak. (Score:2)
Re:but the evidence is still relatively weak. (Score:2)
And yes, they really did invent it. Honest. See, for example, this link [hitmill.com] if you don't believe me.
The particle explains nothing. (Score:5, Insightful)
More correctly, the existence of the Higgs boson validates an assumption in a theory and theory is what claims to explain why all other particles have mass. The important thing to remember is that these are theories that are explaining things; real world particles explain nothing.
Re:The particle explains nothing. (Score:1)
I would be careful of pissing off the Higgs boson if I were you. If it decides to stop explaining your mass, you're in trouble!
It's true! (Score:1)
The real stuff (Score:5, Informative)
Re:The real stuff (Score:4, Informative)
spaces (Score:2)
Useful resource (Score:5, Informative)
Weighty matter (Score:1)