higgs particle found?

[ydoaPs]

http://www.sciam.com/article.cfm?chanID=sa006&articleID=000005FC-2927-12B3-A92783414B7F0000&pageNumber=2&catID=2

[timo]

Is that a question? The answer is in the text:

The Large Electron-Positron Collider (LEP) at CERN, the European laboratory for particle physics near Geneva, operated over a mass range that had a significant chance of including a Higgs boson. It did not find one - although there was tantalizing evidence for one just at the limits of the collider's energy and intensity--before it was shut down in 2000

To elaborate more: We had a talk by one of the CERN Higgs people last month (so it´s most probable that he knew the data from 2000). He did not mention any direct experimental evidence found for the Higgs so far, not even hints on it. So I´d consider the "tantalizing evidence for one just at the limits of the collider" the usual "we need more money to build a larger collider" statement.

That´s nothing special. I read up some papers on extra neutral gauge bosons some weeks ago. It was interesting how the estimated mass of this additional particle (Z-Prime to be exact) increased with the year the respective article was published. Allways just above the mass range allready ruled out by experiment.

Other than that "tantilizing evidence", the article just seems like a review of the Standard Model and Supersymmetry to me.

 

One thing that imho is worth mentioning in this context: Supersymmetry gives an upper bound to the Higgs mass (can´t remember why, atm) at around 140 Gev (I think). This is in a range such that if the Higgs will not be found at the LHC, at least some very promising SUSY theories are ruled out. Of course, I hope that we find the Higgs.

[ydoaPs]

i asked because of the caption. i have a short attention span sometimes, so i didn't read the whole article yet. i have to break it up when that happens.

[Severian]

There was an excess in the expected signal for the Higgs boson at LEP at about 114GeV, at one point as high as 3 standard deviations, but with more data it went away again, so it must have been a statistical fluctuation.

 

They will definitely see it at the LHC though. The Standard Model will not work above about 700GeV in energy if the Higgs boson does not exist and since the LHC will probe higher than that in energy, it is guaranteed to find something.

 

Athiest is correct that supersymmetry puts a limit on the Higgs mass too. For the minimal model it is about 130GeV, but you can get it up to about 165GeV for non-minimal models. One of the more interesting things though is that you can decouple the Higgs boson slightly in these extended models, so that it coud be much lighter than the Standard Model 114GeV bound and not have been seen at LEP.

 

As for the theorized Z' mass increasing with time, I must point out that the same thing happened with the top quark. Go look at papers from the eighties and you will see numbers like 20GeV banded about. In fact, the top quark was often used to criticize supersymmetry because supersymmetry needed a very high mass top quark of about 200GeV or so. People thought that was unnatural and therefore supersymmetry must be wrong. That is until they discovered the top quark at 180GeV....

[Severian]

So no-one wants to know more about the Higgs boson or supersymmetry?

[Jacques]

I Google and found http://www.phy.uct.ac.za/courses/phy400w/particle/higgs.htm

One of the one page explaination ( http://www.phy.uct.ac.za/courses/phy400w/particle/higgs2.htm ) compare the Higgs field to a viscous liquid to explain inertia. I will need force to overcome the vicosity to start moving a mass but I will also need a force to keep it moving... I think it is not a good analogy.

From the 5 one page descriptions, which one is the closest to what is a Higgs boson ?

[Severian]

Well, the third one won the prize, so one would assume that that is best. (I am biased, so not a very good judge.) But they all have merit.

[ydoaPs]

can you tell me why a Higgs field could produce negative energy if it is supercooled?

[Severian]

I am not sure what you mean. Are you confusing symmetry breaking via that Higgs mechanism with symmetry breaking in superconductors?

[ydoaPs]

no, i quoted a passage from TFOTC that said if the higgs field supercooled, it could have caused the expansion of the universe...where did i quote it at...