Discovery of a new particle consistent with the Higgs boson
Early morning on 4 July 2012, at a seminar at the CERN laboratory in Geneva, Switzerland, the two LHC experiments ATLAS and CMS announced independent observations of a new particle in the mass region 125-126 GeV that is compatible with the Higgs boson.
"The results presented here today are the result of over 20 years of effort by several thousands of scientists throughout the world, and Argonne's contributions to the ATLAS detector made possible the acquisition of the data we're discussing today. This is a historic milestone--but only the beginning as we start the task of exploring the properties of this new particle" said Argonne senior physicist James Proudfoot.
A candidate event of a Higgs particle decaying to four muons captured by the ATLAS detector. (image credit CERN)