Part three of a three part series, here their two separate experiments decribed at the LHC - Atlas and CMS - have been conducting independent searches for the Higgs. Because the Standard Model does not predict an exact mass for the Higgs, physicists have to use particle accelerators like the LHC to systematically look for it across a broad search area.
A level of "five sigma" is required to claim a discovery, meaning there is less than a one in a million chance the data spike is down to a statistical fluke. Another complicating factor is that these tantalising hints consist only of a handful of events among the billions of particle collisions analysed at the LHC. Professor Rolf-Dieter Heuer, director-general of Cern told BBC News: "We can be misled by small numbers, so we need more statistics," but added: "It is exciting." If it exists, the Higgs is very short-lived, quickly decaying - or transforming - into more stable particles. There are several different ways this can happen, which provides scientists with different routes to search for the boson.
They looked at particular decay routes for the Higgs that produce only a handful of events, but have the advantage of having less background noise in the data. This background noise consists of random combinations of events, some of which can look like Higgs decays.Other decay modes produce more events - which are better for statistical certainty - but also more background noise. Prof Heuer said physicists were "squeezed" between these two options. Prof Stefan Soldner-Rembold, from the University of Manchester, called the quality of the LHC's results "exceptional", adding: "Within one year we will probably know whether the Higgs particle exists, but it is likely not going to be a Christmas present." The simple fact that both Atlas and CMS seem to be seeing a data spike at the same mass has been enough to cause enormous excitement in the particle physics community.
A level of "five sigma" is required to claim a discovery, meaning there is less than a one in a million chance the data spike is down to a statistical fluke. Another complicating factor is that these tantalising hints consist only of a handful of events among the billions of particle collisions analysed at the LHC. Professor Rolf-Dieter Heuer, director-general of Cern told BBC News: "We can be misled by small numbers, so we need more statistics," but added: "It is exciting." If it exists, the Higgs is very short-lived, quickly decaying - or transforming - into more stable particles. There are several different ways this can happen, which provides scientists with different routes to search for the boson.
They looked at particular decay routes for the Higgs that produce only a handful of events, but have the advantage of having less background noise in the data. This background noise consists of random combinations of events, some of which can look like Higgs decays.Other decay modes produce more events - which are better for statistical certainty - but also more background noise. Prof Heuer said physicists were "squeezed" between these two options. Prof Stefan Soldner-Rembold, from the University of Manchester, called the quality of the LHC's results "exceptional", adding: "Within one year we will probably know whether the Higgs particle exists, but it is likely not going to be a Christmas present." The simple fact that both Atlas and CMS seem to be seeing a data spike at the same mass has been enough to cause enormous excitement in the particle physics community.
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