ATLAS is a particle physics experiment at the Large Hadron Collider (LHC), located at CERN. As one of the two largest detectors at the LHC, ATLAS records head-on collisions of extremely high-energy protons. The collaboration then searches through these collisions for signs of never-before-seen particles and interactions.

In 2012, ATLAS and its sister experiment, CMS, announced the first experimental observation of the Higgs boson, a particle whose existence supports the theory that a “Higgs field” imbibes some particles with mass. Without mass, matter as we know it would not exist and the universe would be a very different place. (Learn more about U.S. participation in the Higgs discovery on the U.S. LHC website.)

Continuing SLAC's long tradition in high-energy physics, ATLAS is a top priority of SLAC's work in particle physics. The laboratory is involved in a wide spectrum of activities for the ATLAS collaboration, from detector operation to explorations of LHC physics.

The group’s physics activities focus on searches for processes and particles that are not explained by the Standard Model of particle physics and on further measurements of the Higgs boson. SLAC also develops computational tools for use in the analysis of ATLAS data with an emphasis on jet algorithms, b-tagging, and jet substructure, and holds significant responsibilities for the computer code that determines which data might contain interesting events and which data does not. As a Tier2 LHC computing facility, the laboratory provides strong support for data analysis and simulation efforts.

In addition, SLAC plays a major role in the operation of the ATLAS pixel detector. Like a huge digital camera, this detector records information about what happens after two protons traveling toward each other at nearly the speed of light collide. This work builds on SLAC's long experience in silicon detector technology. SLAC will also offer important contributions to planned upgrades to the ATLAS detector, including the future particle tracking upgrade.

Visit the SLAC ATLAS group website » Visit the ATLAS Confluence site for more technical info »