Neutrinos, Muons and the Standard Model

scorp1us writes: "I can't believe I haven't seen this posted yet. Apparently experiments in particle physics aren't holding to theory. The result: a search for a new form of energy or matter. Read about it in the Post. No wonder witches weigh as much as a duck."

Comments

Um...yeah?

[BMazurek]

I can't believe I haven't seen this posted yet.

I think it was posted yesterday. It just didn't reach the front page.

That article had many more references, too...

Not Reviewed Yet

[TheBoquaz]

I found it interesting that these "results" ended up in the media before being accepted by the Journal they are publishing in.

In science, especially physics, there is a tradition of review which has caught many claims such as this before.

It is likely that they have missed some minor force or effect in thier Standard Model calculations, or that we simply need to understand neutrinos better.

Until a Physical Review Journal accepts research, and even sometimes after that, it should not be viewed as anything more than fantasy.

Follow-up experiments.

[Christopher Thomas]

"On a statistical basis, that would be a 1 in 400 probability of happening as a result of chance. "

That doesn't seem like a big deal to me. That sounds more like a problem in the experiement. I don't think anyone should be jumping for joy at this discovery until they duplicate it in another test.

This *is* a duplicate experiment - or close to it. Check the previous Slashdot article on the subject. This project is measuring a value that was measured by three previous experiments. Two of the previous experiments gave a very wide range for results, and the other one gave a narrow range for the results consistent with this experiment's results.

Re:More forms of matter?

[Mr. Slippery]

I thought the guys who won the Nobel Prize for Physics already discovered a new form of matter. Is this more of their findings, or something totally different?

Totally different. The Nobel guys found a new state of matter, the Bose-Einstein condensate.

Does this mean that there could be 2 new forms of matter to bring the total up to 5 forms?

There's already (at least) 5 states of matter: solid, gas, liquid, plasma (gas so hot that it gets ionized - the sun's made out of it), and the recently confirmed Bose-Einstein Condensate (gas so cold that weird quantum things start to happen).

You've also got the degenerate states of matter found in white dwarfs (where the electrons squeeze together), neutron stars (where the electrons smush into the nucleus), and black holes (where...well, it all breaks down there). These don't seem to be counted in the usual enumeration of states of matter, but then they've never been produced on Earth, they're really still theoretical.

What they'd be looking for out of this new discovery is more along the lines of a new fundamental particle or force.

Re:Always wondered...

[MarkusQ]

...the principle of falsifiability has gone out of vogue...Karl Popper...shifted to a weaker form...post-modern critiques...have eroded its popularity greatly...scientific propositions require auxilliary hypotheses to have any predictive value. When a specific prediction is falsified, it is possible to "get around" the problem by modifying the auxilliary hypotheses. Since such modification to auxilliary hypotheses is considered a normal part of the scientific process, falsifiability doesn't really work very well.

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Could you give some examples of what you're talking about? For the record, I work in biotech, and pretty much our whole business is built on falsifiability; I've never heard a working scientist argue seriously against it.

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I'll take a stab. Suppose I say "It's raining outside." This sounds like a classicly falsifiable statement. But is it? If you look out the window and don't see rain, it may be that I was wrong. Or (I could perversely argue) it could be that you (incorrectly) assumed that

1) by "outside" I meant "outside, near this building" not "outside, somewhere"

2) the rain would be all around, not just on the side of the building with the window

3) the rain drops would be large enough to see

4) there would be enough rain drops to notice

5) it would still be raining by the time you looked

6) enough photons would interact with enough raindrops before reaching your eyes that you would detect the rain (instead of all missing)

7) the window really is a window, and not a clever high-res display

...and so on and so forth. The point is there are an infinite number of these silly secondary assumptions needed to go from "it's raining outside" to "if I look out that window I should see rain"; failure of the second claim does not falsify the first.

The hard core rationalist claim that "all it takes is a single counter example to disprove a theory" doesn't really work. In practice, then, we deal with a sort of fuzzy-falsification, and come up with estimates (w. specified confidence levels) that an assertion is true or false. A single test can't really topple a theory since you can't know for sure that the problem was in the theory and not in your test.

Make sense?

-- MarkusQ

Re:Not that significant

[Zeinfeld]

I wouldn't make any long term plans based on this paper. The "one chance in 400" is misleading -- if you look at the paper, what it's really saying is that their experimental result differed from their theoretical result by three standard deviations (three sigma). On the face of it, this isn't very impressive. The trouble with straightforward statistical analysis in this fasion is that particle physics is hard. Experiments are being done at the limits of detectability, and often in ways that have never been done before.

As a former experimentalist in the field (they gave me the Phd so I couldn't be all that bad) I am not getting excited.

The problem is that the experiments are simply not accurate enough to jump up and down in celebration for such a miniscule deviation.

What I am really suspicious about is that the number of observations is much lower than expected. That can happen because you just missed some particles you should have seen.

You can have a deviation that is 'significant' at twenty or a hundred standard deviations and it can still be the result of experimental error rather than a flaw in the standard model.

Given the way the physicists write their programs I would not be at all surprised if this turns out to be no more than the result of a flaw in PAW or GEANT. A physicist will go off to beg congress for a billion dollars to four experiments on the same accelerator (e.g. LEP) so that each can cross check the results of the other. Then they will all share the same analysis programs even though they are known to be riddled with bugs. And don't start on about the Web, first off the Web code was not built on a twenty year old code base from the dawn of Fortran, second there were multiple versions of the code written from the very start. In 1992 there were 10 browsers and at least 5 Web servers.