Victorinox Classic Knife: Physicists find hints of a light Higgs boson in LHC data

During Ars' trip to Fermilab earlier this spring, the staff was excitedly talking about their expectations for the summer. That's when the high-energy physics community has many of their meetings, and the expectation was that all of the major players—DZero and CDF at Fermi, and ATLAS and CMS at the LHC—would process as much data as they could and update the community on the search for things like supersymmetry and the Higgs boson, a particle that helps give all others mass. Right now, the Europhysics Conference on High Energy Physics is happening in Grenoble, France, and the folks from Fermi will not be disappointed. The first results from the LHC have greatly expanded the mass range in which the Higgs won't be found, and left open the possibility that it might eventually turn up in the area of 140GeV.

Results have been presented by people from both ATLAS and CMS. Each of these has looked for evidence of the Higgs in different "channels," with each channel representing a different process for producing a Higgs, which will then decay into a spray of distinct particles and photons. (Symmetry Breaking has a decent explanation of some of this.) Each one of these channels is sensitive to a different range of energies, both because of the process that triggers the event, and because the background of similar-looking events also depends on the energy. As a result, you get a complex set of graphs, each generated in a different channel.