CERN Announces Collider Startup Delay

perturbed1 writes "The 142nd session of the CERN Council saw Organizational Director General Robert Aymar announcing a delay in the activation of the Large Hadron Collider (LHC). The installation will start up in May 2008, taking 'the first steps towards studying physics at a new high-energy frontier.' Such a delay was foreseen due to the quadrupole accident, which we've previously discussed. This gives extra time for Fermilab physicists to try to understand the latest interesting hints of the Higgs boson, as well as give much needed extra-time for the detectors at CERN to get ready for data taking. Given that it will be fall before the LHC detectors take any useful data from collisions at 14TeV, could Fermilab collect enough data for a 5-sigma discovery by then?"

Higgs boson

[the_kanzure]

The Higgs boson subatomic particle [web.cern.ch] is theorized to be the material unit from which mass originates.

Shortly after the birth of the Universe in the Big Bang, as the universe expanded the temperature fell below a critical value where a new type of field developed everywhere in the Universe (field, cmp. magnetic field around a magnet. Every point in space has a property: a measurable magnetic force and direction). We call this particular field the Higgs field. Some particles coupled to this field and the property they acquired is what we measure as mass. That is, particles are not solid in themselves but can be seen as a wave on a water surface. Although a wave moves no water from one side of a lake to another, it carries a lot of information: energy, momentum, amplitude, wavelength, etc. For particles mass is just another property acquired by interacting with the ever pervading Higgs field and that property we perceive as mass.

Re:I for one...

[BitterOak]

No, I don't wish any harm to the scientists or their reputations. However, I think it would be fun if Gravity didn't fit so nicely in the Standard Model like everyone is hoping it will.

Your point is well taken in that in some ways it would be more interesting if the Higgs were not found, but in fact the Higgs does nothing to bring gravity into the Standard Model. Instead it would explain the symmetry breaking in the Electroweak interaction. (I.e. why the W and Z are massive while the photon in massless.) Without a Higgs, a new mechanism would be necessary to explain this.

Re:I for one...

[Thiago Tomei]

I'd like to point that the Higgs boson has NOTHING to do with gravity. The Standard Model, Higgs boson included, is a theory of the strong and electroweak interactions. The mass that fundamental particles have for virtue of their Higgs couplings is akin to an inertial mass only.

But I agree with you. I'd also hope for the non-existence of the Higgs boson. however, all odds are against us. There are some fundamental processes that can only be made sense of in the presence of a particle which looks very much like the Higgs. If I recall correctly, it was Chris Quigg that said that "if the Higgs boson does not exist, we'll need something much like it". But of course, with the Higgs come a lot of other issues (the hierarchy problem for instance), which open up a whole new area for physics.

Re:Time is running out for Fermilab

[s4m7]

What you are referring to is the 4th related article: "Search for Higgs 'God Particle' gets interesting." It had been rumored that Fermilab had seen something that they were keeping under wraps for the summer publication cycle. Speculation was that it was the Higgs Boson but turns out it was the Cascade B. [slashdot.org]

Fields are not aether

[the_kanzure]

That sounds like Aether to me.

Nah, fields are mathematical formulations. Quantum field theory [universe-review.ca] provides the virtual particles [ucr.edu] that more physically explain force interactions via probability amplitudes and so on. In fact, this is exactly what gave Feynman [zyvex.com] his quantum electrodynamics [gsu.edu] and subsequent Nobel prize (that he disliked).

Link to plot

[Roger W Moore]

Sorry I should have included this in the original comment. Here [fnal.gov] is a link to the original expected Tevatron sensitivity and the updated one. The y axis is the volume of data collected by both experiments i.e. sum of DØ and CDF datasets and the x axis is the mass of the Standard Model Higgs. This is currently limited to be above 114 GeV/c2. The three lines are 5-sigma discovery, 3-sigma evidence and 95% confidence limit if we don't see any Higgs event in that amount of data.

The dip round 160 GeV/c2 mass is because a heavy enough Higgs can decay differently than a lighter one and the different decay is a lot easier to detect above all the other "background" events happening in the detector. We should get 10-20 fb-1 between both experiments by 2009 so, as you can see, unless we do something clever (which had not been thought of at the time the plots were made) or the Higgs is really light we won't get 5-sigma, but 3-sigma is a real possibility.

Bad Example

[Roger W Moore]

Actually a magnetic field is a bad example for a Higgs field precisely because it has both a magnitude and direction. The Higgs field has only a magnitude. A better example would be the temperature map you see in a weather forecast. Everywhere has a temperature value: it has no direction. This is what makes it different from the "aether" (aether had a preferred direction which is why the Michelson-Morley experiment disproved it).

The other weird thing about the Higgs field is that it has its lowest energy density at a non-zero value of the field i.e. it requires energy to lower the Higgs field! Electric and magnetic fields have their lowest energy density when the field strength is zero i.e. it takes energy to make them non-zero.

Re:Time is running out for Fermilab

[Gromius]

As a physicist who works at a Fermilab experiment, may I just say those reports were utter crap. A lot of excitement over nothing. It was completely unconvincing. Basically it was one guy with a blog making claims he really shouldnt have.

Something interesting to note, as an experiment winds down, it tends to "discover" something, recently this tends to be the Higgs. Compare this to 2000 when LEP at CERN was shutting down, passing the torch to the Tevatron at Fermilab, and there was all the commotion about the "Higgs discovery" there by ALEPH.

Anyway at the moment we have lots of bumps in our mass spectra which is how we find particles. However its a statistical process so bumps can naturally form just by chance alone. Factor in that we are looking in hundreds of places and all of a sudden a few bumps that have a probability of one in a few hundred of occurring dont seem so exciting yet. Not saying theres nothing there but we've seen this so many times before and it turns out to be nothing, people just tend to get to excited when they see them.

However Fermilab has a good chance of getting the Higgs (if its the Standard Model Higgs) because it has to be relatively light to make other measurements consistent which means its in the easiest spot for the Tevatron to see it but the hardest spot for the LHC to see it. It'll be well past 2009 before the LHC has a hope of seeing the Higgs at a low mass but it could see a high mass Higgs pretty quickly after turning on.