Showing posts with label LHC. Show all posts
Showing posts with label LHC. Show all posts

Tuesday, December 13, 2011

Unofficial Higgs combined plots are in
























As promised, Philip Gibbs has produced combined plots for the Higgs mass, which includes data from LHC, Tevatron and LEP. Notice that nice peak centered at 124-125 GeV!

If this is a light E6 GUT Higgs, we'd expect to see a light isosinglet quark such as the D quark at the LHC very soon. We should even be able to predict its mass (~>250 GeV). A Z' boson would also be nice. For more info, see slides here and here. On to 2012!

Higgs rumors were correct













The official results are in, at least for the LHC's 2011 data, and it appears the rumors were quite accurate. See TRF and QDS for further details. To quote CMS member Dorigo, who stated there is now "Firm Evidence" with the current data,

So the summary is that ATLAS has a 3.6-sigma significance at 126 GeV, by combining their three most sensitive channels; CMS has a 2.4-sigma significance at 124 GeV, by combining all the meaningful search channels -even less sensitive ones.

After an ATLAS and CMS combined plot is produced, there might very well be over 4 sigma evidence for a light Higgs. I'm certain Philip Gibbs is working on a combined plot at this very moment. There is still a Christmas present to be delivered! Stay tuned.

Monday, December 12, 2011

Why a light Higgs is cool













As to why many theorists are excited over news of a possible light Higgs boson with 125 GeV mass, here's a memorable excerpt from a September 2011 interview with Clerk Maxwell Professor of Theoretical Physics and former CERN staff member John Ellis:

In the first scenario (114-135 GeV), we could be looking at a Standard Model Higgs boson. This range has been refined experimentally: recent LHC results presented in Mumbai excluded the Standard Model Higgs from about 135 GeV to about 500 GeV, while LEP had previously excluded it up to 114GeV. That leaves a narrow low-mass range of about 20 GeV where it could lie. But if found in this range, the Standard Model theory would still be incomplete; the present electroweak vacuum would be unstable for such a light Higgs in the Standard Model, so we would have to come up with new physics to stabilise it.