Question on Particle Physics (i.e. the "God Particle")

[Eeezee]

Originally posted by: firewolfsm
From what I've heard, the Standard Model is the best theory we have that combines the fundamental particles, but recent experiments have begun to deviate from what the standard model expected. We've patched it so account for these experiments, but that's usually a hint that things are going downhill.

We'll find out more in a couple weeks when the LHC goes online.

You wish! It'll be years before the whole thing is completely calibrated! Turning the LHC on doesn't mean anything without accurate detectors.

The LHC is going to start at low luminosity (ie it won't be much better than other particle colliders at first). The detectors (ATLAS and CMS primarily) will be turned on and calibrated such that certain standard candles match known, expected results (such as Z->ee). When everything starts up, nothing is going to quite work as expected - hundreds of researchers will be writing code to compensate for this and that, some detection cells will be ignored completely (equipment failure - for example, the CMS electromagnet calorimeters are made of scintillating lead tungstate, but these crystals have a tendency to yellow VERY easily and may not make it past the calibration phase).

Once calibration is complete to satisfaction, the data will have to be analyzed. This is probably also going to take several years. In order to be truly sure that you've seen the Higgs, you need a HUGE dataset. Just storing the sheer volume of data has been a huge technological challenge, not to mention the method for transferring these enormous datasets to the various high energy groups that will be using data analysis.

Yeah, a few weeks isn't quite going to cut it. I expect we'll be in the next decade by the time the Higgs is announced.

And then ATLAS will discover the Higgs and any cool new physics first and the CMS people will be mocked relentlessly

You can expect that the paper announcing the detection of the Higgs will have a 100+ page author list

 

[Eeezee]

Originally posted by: silverpig

Originally posted by: bsobel

Originally posted by: firewolfsm
If the higgs even exists. People become far too caught up in contemporary physics theory and forget that that's exactly what it is, theory.
Remember when we talked about string theory as if it were fact?

Used to? M-Theory is still the leading canidate for the GUT, all 5 flavors of string theory fold up nice and pretty into it.

Not really... Most physicists favour a modification/addition to the standard model over string theory. It's still only accepted as a purely outside shot in the dark.

Let me put it this way: You're buying a house. You have your down payment set, you have your financing in order and you've budgeted for the monthly mortgage payments. But you still have that lotto ticket for the weekend...

Experimentalists don't care for string theory - I guess "don't care about" would be a better term. It's not testable. A theory that is untestable may be theoretically groundbreaking, but without experimental data it is hard to take seriously.

 

[DrPizza]

If you're confused at all about where these particles "come from", I suggest spending an hour or two at www.particleadventure.org

I think that on one of the pages, the analogy they use is of smashing two grapes together at very high speeds and out pops watermelons which decay into grapefruits, oranges and bananas.

 

[beelzebubthe2d]

Originally posted by: silverpig
Not really... Most physicists favour a modification/addition to the standard model over string theory. It's still only accepted as a purely outside shot in the dark.

Says who? If you took a survey of people qualified to have an opinion on such things, the vast majority would agree that no tinkering with the SM is going to produce a quantum theory of gravity. String theory might not be right, but at least we know it's not wrong.

 

[Eeezee]

Originally posted by: beelzebubthe2d

Originally posted by: silverpig
Not really... Most physicists favour a modification/addition to the standard model over string theory. It's still only accepted as a purely outside shot in the dark.

Says who? If you took a survey of people qualified to have an opinion on such things, the vast majority would agree that no tinkering with the SM is going to produce a quantum theory of gravity. String theory might not be right, but at least we know it's not wrong.

By physics experimentalists everywhere. We consider string theory a "shot in the dark" because we haven't thought of a good way to test it yet. Sure, people are talking about the LHC perhaps providing some credence to string theory if certain things happen, but the absence of those events at the same time does not necessarily disprove string theory, either. Ultimately, it's a theory that we have no way of verifying (as far as we know).

Have you ever read about the history of string theory? It's very interesting to follow the way in which a new physical model is established, how experimental contradictions would require modifications in the model (sometimes the theorists would completely start over), etc.

 

[silverpig]

Originally posted by: beelzebubthe2d

Originally posted by: silverpig
Not really... Most physicists favour a modification/addition to the standard model over string theory. It's still only accepted as a purely outside shot in the dark.

Says who? If you took a survey of people qualified to have an opinion on such things, the vast majority would agree that no tinkering with the SM is going to produce a quantum theory of gravity. String theory might not be right, but at least we know it's not wrong.

Uh, most of the non-string theorists in the department I work in?

Check out loop quantum gravity, it's got potential to be a quantum theory of gravity without destroying the standard model.

 

[RideFree]

Anybody read a good book lately?
Leon Lederman, The God Particle, (Houghton Mifflin, Boston, 1993),