Higgs boson announcement for 4th of July?
Posted by Xeno on July 2, 2012
Has the Higgs boson finally been detected? It’s almost gotten to the point that if a discovery of some sort doesn’t come out of next week’s update on the multibillion-dollar subatomic search, it’ll be a big surprise. But how far will the announcement go, and what will it mean for the future of physics?
To refresh your memory, the Higgs boson is the only fundamental subatomic particle predicted by theory but not yet detected. It’s thought to play a role in endowing some particles, such as the W and Z boson, with mass … while leaving other particles, such as the photon, massless. The Higgs mechanism, proposed by British physicist Peter Higgs and others in the 1960s, could have played a role in electroweak symmetry breaking, which was a key event in the rise of the universe as we know it.
The Higgs boson is so key to the current understanding of fundamental physics that Nobel-winning scientist Leon Lederman nicknamed it the “God Particle” — a term that has been making other physicists wince ever since. Another religion-tinged cliche would be to call it the “holy grail of particle physics,” as CERN physicist John Ellis has. He says finding the Higgs is a key goal for the $10 billion Large Hadron Collider.
“That’s one thing that we’re really looking forward to with the LHC,” Ellis told me five years ago. “In fact, back when we persuaded the politicians to stump up the money to build the thing, that’s probably what we told them.” …
…When physicists talk about their confidence, they talk in terms of statistical “sigma” levels. The higher the sigma, the less likely that the results are just a fluke. In particle physics, 3 sigma constitutes strong evidence, but it takes 5 sigma to accept the results as a discovery. At the 5-sigma level, statisticians say there’s roughly one chance out of 3 million that you’re leaping to the wrong conclusion, as opposed to a 1-in-1,000 chance at the 3-sigma level. That distinction makes a big difference when you’re sifting through billions upon billions of proton-on-proton collision reports.
Last year, the best that the LHC teams could do was 3.6 sigma for ATLAS, and 2.6 for CMS. Now physicists are looking for a 5.
For three weeks, the teams have been running the numbers on their experimental results in secret, so as to avoid any chance that one analysis will influence the other. Their results are to be announced during a presentation at the CERN nuclear research center in Geneva, which will be webcast starting at 9 a.m. CEST (3 a.m. ET) on July 4. Although no official word has leaked out, the unofficial word is that someone looking for a discovery could get to the magic number.