But how did the physicists know they found one? What were they looking for? And in the highly improbable chance that the press reports a breakthrough in physics that doesn’t turn out to have happened, could they be mistaken?
Smash particles together at near light-speed and the momentary very high energy collision causes a Higgs Boson to appear and then immediately disintegrate. The maths show what energy range it should be and how it should break down. And after millions of smashes, the tell-tale disintegrations with the correct expected properties show up enough times that it can’t be random noise.
The God particle?
You should know, if you have to ask, just forget it.
Two demerits for using that term.
It’s a joke.
So are the demerits.
They expected to find an uncharged spin-zero particle in a certain mass range. They did find an uncharged spin-zero particle in that mass range. They don’t know for certain that it’s the Higgs, but if it isn’t, then they don’t have a clue what it is, nor why they didn’t find the Higgs.
Isn’t Higgs, by definition, an uncharged spin-zero particle in that mass range? (Honest question.)
Yes. Chronos was getting to the epistemological challenge where people say, “sure, you found an uncharged spin-zero particle in the expected mass range, but how do you know it’s exactly the one you were looking for and not some other surprising uncharged spin-zero particle in that mass range?”
Basically, Chronos was saying, if it what they discovered wasn’t the Higgs Boson, then reality has some ‘splainin’ to do.
Fair enough. I guess my question should have been: what other properties did Dr. Higgs, et al., predict about the Higgs boson (other than spin-zero, uncharged, in that mass range) that the particle they actually found hasn’t (yet) been shown to possess?
See my links above.
An important part of the Higgs-ness of the Higgs is its decay rates to other particles. The whole “the Higgs gives fundamental particles their mass” thing is intimately tied to how readily the Higgs decays into those same particles, since the underlying parameter that governs a particle’s mass also governs its interaction rate with the Higgs.
If you want a graphic, you could see p. 13 of this PDF set of slides that the CMS collaboration presented yesterday. On that page, the plot on the right shows the measurement and error bar for the rate of the Higgs decaying to various things. The plot is scaled such that the Standard Model predicts 1 on the horizontal axis for a simple Higgs.
The bits in parentheses are Higgs production modes or process “tags” – another important Higgs fingerprint. The Standard Model makes specific predictions about which proton-proton collision processes should make a Higgs, how often they should do so, and what other things should be produced alongside (allowing one to “tag” the specific process).
Some of the error bars are still quite large, indicating that more data is needed to pin down some of the processes, but so far everything is consistent with the Standard Model expectation.
For completeness, I should note that I chose the CMS slides at random and could have chosen the ATLAS collaboration’s slides. A nice feature is that two rather independent experiments see consistent results.
So I’m gathering that unlike FTL tachyons the Higgs boson experiments are consistent with the predictions. I suppose there’s so room for error to be found in the measurements, but this one seems to have a more reasonable basis.
So what’s next? The particle predicted to exist does exist, aside from confirmation does this lead to new theory, plug holes in old ones, bring us closer to understanding the whole shebang?
Finding the Higgs is basically a dotting-the-I’s-and-crossing-the-T’s thing for particle physics as it’s currently understood; we were pretty sure that it should exist, and now we’re pretty sure that we’ve found it. What most physicists are really hoping for out of the LHC now is the discovery of a completely new and unexpected particle to study.
In physics departments these days, you’ll often hear the opinion that the worst outcome for particle physics would be if the LHC finds the Higgs boson and nothing else. Not finding the Higgs would have forced a wholesale revision of our models, and could have led to new predictions to test experimentally. Finding new particles would, of course, give the experimentalists something to study and the theorists something to model. But if the LHC doesn’t find anything new now that it’s found the Higgs, and the Higgs behaves exactly the way we expect, then there’s no obvious direction for the field to go other than building an even bigger collider. And who’s going to want to pony up the dough for a multi-billion-dollar project like that when we have no idea whether it’ll detect anything at all?
List of unsolved problems in physics
Problems with the Standard Model
Both of these pages are rather incomplete, but even with what’s shown they give a good sense of how much we don’t understand.
The Higgs observation is one step along the road to understanding. It was a big one since the “Higgs mechanism” is so deeply rooted in the gears of the Standard Model (to mix my metaphors). The prediction that a corresponding Higgs particle with such-and-such properties should exist hinges on nearly every fundamental aspect of the descriptive framework (including many that cannot be tested other ways), so establishing its existence is key to knowing whether you’re way off the mark or whether your theory has legs. It would be nice to break the Standard Model irreparably or to find a deeper theory that the SM is an approximation of due to the many unattractive features of the SM, but so far, no dice.
Pasta,thank you!
Tripolar I hope you took my query as a complement, not a hijack!
In addition, I read the first of moriah’s links when it came out in the NY Times. it was a fascinating account of the way the two teams worked to find the particle. I’d highly recommend it for any lay person who wants some insights into the way big-science is done.
Not a hijack at all. I just wanted to get the ball rolling on this topic.
The cynic in me says when you spend billions of dollars to look for somethng you better find it. LOL
It reminds me of the claim that Shakespeare’s play were written by another man named William Shakespeare.