The images shown here are visualizations of the data taken with the ATLAS detector at CERN's Large Hadron Collider. A Chicago High Energy Physics group under the leadership of Jim Pilcher played a major role in designing, building and running this state of the art apparatus. On the upper left is a view of ATLAS from the perspective of the beam line sending the protons to their doom; under it is a view perpendicular to the beam. The energetic particles denoted by green and red have been identified as a muon and electron, respectively; they might be the products of the decay H -> WW -> e νe μ νμ. The zoom-in on the lower right shows that the electron and muon come from a common origin, and that the LHC beam is so intense that we often see several collisions per event.
It is an observed excess of such events over similar events expected from Standard Model backgrounds that strengthened the discovery of the new particle. A Chicago effort by posdoctoral scholars Antonio Boveia and Peter Onyisi played a major role in the anaylsis of this decay channel, which was statistically added to other channels such as H-> γγ to identify the new particle at 126 GeV. The HEP group will be studying this new resonance for the forseeable future. The new resonance is unique in the particle world: a neutral boson, likely with spin zero. We will continue to study the properties of this resonance to determine if it is the "minimal" Higgs boson, or some other manifestation of new physics.
Five Chicago faculty currently focus their research on ATLAS physics: Young-Kee Kim, Frank Merritt, Mark Oreglia, James Pilcher, and Mel Shochet. In addition to the Higgs search, they are making precision measurements of Standard Model processes, searching for other new physics, such as SuperSymmetry, and designing upgrades for the future running of ATLAS. The group receives important support from Rob Gardner of the Computation Institute -- Rob developes innovation in grid computing tools that allow us to process the unprecedented amount of data streaming in from the LHC. The Enrico Fermi Institute's Electronics Development Group designed fast, state of the art electronics for ATLAS, and continues to contribute as we design upgrades for higher energy running.