Will it really take ATLAS 3 years to see 5 sigma Higgs? August 20, 2008Posted by gordonwatts in ATLAS, CERN, D0, Fermilab.
Probably (for ATLAS new predictions on this should be released in a few months). But in the context of the Tevatron and the LHC Higgs search that isn’t really what is important.
The ATLAS prediction that it might take 3 years to reach the 5 sigma level for a low mass Higgs discovery got a lot of airplay. It got me to thinking. Lets say the two accelerators are in close competition for the Higgs. The Tevatron can really only speak to the 3 sigma level. It isn’t ever going to get to the 5 sigma level. Further, at the Tevatron the CDF and DZERO experiments will have to combine their results to even reach this 3 sigma level. So, I find it highly unlikely that the LHC will sit back and let the Tevatron get away with this. I certainly wouldn’t (and I’m on a LHC experiment). So what to do? Obvious – beat the Tevatron at its own game: combine results from CMS and ATLAS and the 3 sigma level will be obtained much more quickly. At that point the LHC has stolen the thunder from the Tevatron and CMS and ATLAS can now race each other to individual discoveries of the Higgs at the 5 sigma level.
I don’t expect the experiments to combine for the 5 sigma discovery (I could well be wrong, of course – I know of no plans to not do this or to do this!). There are many forces at play that are driving each experiment to make the first paper submission of a 5 sigma signal. This may, indeed, be what gives the Tevatron space to slip in with a 3 sigma evidence paper. And in the grand scheme of things – the Tevatron goes out with a 3 sigma evidence and the LHC with a 5 sigma discovery – that doesn’t seem like a bad “split”. But who has ever heard of the free market working like that!?
As a member of DZERO I want to push as hard as possible to nail a low mass Higgs. As a member of ATLAS, I want the experiment to scramble as fast as possible to get the Higgs – evidence and discovery. After all, that is one of the LHC’s main points.