UMass Amherst Physicist Stéphane Willocq to Lead the World’s Largest Particle Collider Experiment

Professor of physics Stéphane Willocq has been elected as the next spokesperson for the ATLAS experiment, a collaboration of approximately 6,000 scientists worldwide who are using the Large Hadron Collider at CERN, in Switzerland, to probe the origins of the universe and to reveal its most fundamental constituents and their interactions. The team is searching for many different kinds of new phenomena, particularly for what Willocq calls the "dark sector," or the mysterious world of dark matter, which has never been directly observed. This is the first time in ATLAS's 30-year existence that a scientist from an institution in the U.S. has been chosen as leader of the experiment.

The ATLAS spokesperson, who serves for two years, is the de facto primary investigator leading the ATLAS effort. Willocq's term as spokesperson will begin March 1, 2025, and he will be responsible for overseeing the operation of the experiment during what's known as "Run 3." The Large Hadron Collider (LHC) smashes protons together at nearly the speed of light, and the coming run will drive protons at the highest energies ever achieved in the laboratory. This will triple the amount of data that ATLAS collected during Run 2, allowing for greater statistical accuracy and opening new areas as of yet unexplored by physicists.

Willocq will also prepare ATLAS for operating at the High-Luminosity LHC, which is expected to start in 2029 or 2030. This new phase of exploration will last for over a decade and will increase the number of proton collisions by a factor of 10. It will be a monumental and exciting effort, says Willocq.