So how will CERN's LHC detect a Higgs boson

[kloptok]

My personal feeling is that CERN will on Wednesday announce a higher sigma level than earlier, but still not the required 5 sigma. If, as is speculated in the Daily Mail article, there will be an announcement of a 4 sigma significance this is not enough to conclude a discovery of the particle. In the Daily Mail article it sounds as if this is a sure discovery, this is not true. Statistical flukes can still happen at this confidence level. We will just have to wait until Wednesday I guess. I think the seminar can be followed live here:
http://webcast.web.cern.ch/webcast/

It would indeed be intriguing if there was no discovery, but at the same time I personally feel that particle physics needs a positive result in order to justify the experiment with the general public. Even though a no-show is interesting theoretically it doesn't sound very good that loads of tax money was spent to discover nothing and it will be difficult to motivate future experiments.

 

[wizwom]

The Tevatron used proton/antiproton annihilation; for those collisions, essentially all the energy in the collision became free energy, and the gamut of possible products was limited only by energy.
The LHC collides hadrons (of which protons are one example) and as such, there are strong force effects which will prefer certain particles. The have a large ion collision experiment (using Pb ions), besides just proton collisions; with their energies, they should see a quark-gluon plasma without differentiation into hadrons for a measurable time.

 

[mfb]

If the SM higgs is there, the expected signal significance in 2012 data should be somewhere around 3-4 sigma (for each experiment), and the combination could give something like 4-5 sigma. However, statistical fluctuations might change this, so more than 5 sigma or just 3 sigma in the combination are possible, too.

I would expect a possible 5-sigma-measurement form the combination of ATLAS+CMS, if no individual experiment already reaches this. But taking more data is the better way to increase the significance*.

*assuming the Higgs is there, which I expect with >90% probability

The Tevatron used proton/antiproton annihilation; for those collisions, essentially all the energy in the collision became free energy, and the gamut of possible products was limited only by energy.

While the Tevatron could use more high-energetic quark/antiquark-annihilations, more than ~50% of the beam energy was very unlikely. Remember that the proton momentum is distributed over 3 quarks and some virtual particles. Hard (quark) collisions use the momentum of one quark (per proton) only for heavy particles.