Tomorrow CERN will announce an important update on their search for the Higgs Boson at the LHC (in case you have just got back from another planet) Expectations are high with some news reports saying they will reach the critical 5 sigma discovery level. Peter Higgs himself has flown over to CERN where he has joined other physicists responsible for the theoretical breakthrough back in 1964 that predicted the Higgs Boson. Sources from within CERN point out that final results will not be ready until today so all prior reports of a discovery can be no more than speculation, we will se tomorrow.
What we do know is that the two experiments that have been searching for the Higgs, CMS and ATLAS will each provide updates including data collected this year at 8 TeV. This could be combined with the results from last years 7 TeV run that were published at the last big update in December. We know that they will not attempt to combine the CMS and ATLAS data together because they have stated that they are now aiming for independent discoveries from the two detectors. Whether they can reach that important 5-sigma level will depend on how much data they can prepare in time. The amount of data available is 6/fb to be compared with the 5/fb from last year. The higher energy gives another 15% advantage in the crucial diphoton channel where the Higgs is seen most clearly.
If they can get that data together it adds up to a signal about 55% stronger than last year when they each had about 3 sigma in the diphoton channel, so this year we might expect at least 4.5 sigma, but it is not that simple. Last years signal was stringer than expected. If that was a statistical fluke for both experiments then it should be weaker this year bringing expectations down to more like 4 sigma. On the other hand if the enhancement was due to real physics it will still be there and they may even be lucky with the random quantum fluctuations and get nearer 5 sigma.
There is one last thing they can do to improve the signal. They can combine information from another channel such as the decay of the Higgs to 4 leptons. Last year this did not provide much help and only added about 0.2 sigma, but with higher energies it may just be a little better, perhaps enough to take them over the finish line. In the end it will be the luck of the fluctuations that counts. They have two experiments so two tosses of te coins. One may make it while the other falls short.
Of course the next set of data due out in September will certainly finish the game for both of them but nobody wants to wait for that after all the build-up. If neither experiment makes it individually they will be close enough to say that the combination of the two certainly adds up to an unofficial discovery, even if they do not do that combination immediately, Which ever way you look at it they will be able to spin the conclusion to provide the media with the result they are waiting for.
And if they don’t? Here is a ray of hope from an AP report
“Scientists with access to the new CERN data say it shows with a high degree of certainty that the Higgs boson may already have been glimpsed, and that by unofficially combining the separate results from ATLAS and CMS it can be argued that a discovery is near. Ellis says at least one physicist-blogger has done just that in a credible way.”
That physicist-blogger is of course yours truly. As usual I will be carrying out the full cube of combinations using my unofficial methods as soon as the plots are available. The viXra combination applet has already been updated with yesterday’s new data from the Tevatron. The results will be a little approximate and certainly not endorsed by CERN, but unofficial discovery is at least guaranteed or your money back.