ORNL’s John Lajoie. Credit: Alonda Hines/ORNL, U.S. Dept. of Energy
John Lajoie of the Department of Energy’s 91°µÍø Physics Division was reelected as spokesperson of the electron-Proton/Ion Collider, or ePIC, Collaboration. With more than 1,000 participants from 25 countries, the collaboration is working to design, build and operate the first experiment at Brookhaven National Laboratory’s future Electron-Ion Collider, or EIC. The U.S. long-range nuclear physics research plan named the construction of the EIC a top priority.
Lajoie was elected ePIC’s first spokesperson in 2023. During his first term, he led the collaboration to finalize the detector technology choices and prepared the experiment for DOE’s Critical Decision (CD) milestones CD-3A in November of 2023 and CD-3B in January of 2025. The CD-3A/B reviews precede approval of the project’s final design and the authorization of construction of the ePIC detector. Reelected to a second two-year term with an overwhelming majority, Lajoie will lead the collaboration in baselining the experiment and starting construction. He will work alongside Silvia Dalla Torre of Italy’s National Institute for Nuclear Physics, ePIC’s deputy spokesperson.
In ORNL’s Relativistic Nuclear Physics group, Lajoie studies the quark-gluon plasma, a phase of matter that existed in the very early universe. A Fellow of the American Physical Society, he is renowned for the development of advanced data collection systems that enabled the discovery of the quark-gluon plasma and leadership in forging the first detector collaboration for the EIC. The ePIC experiment will produce snapshots of the structures of quarks and gluons inside protons and nuclei. Lajoie hopes to gain insight into the strong interaction between quarks that is mediated by gluons.
Lajoie joined ORNL in 2023 from Iowa State University, where he was the Harmon-Ye Professor of Physics. Prior, he worked on Brookhaven’s Pioneering High Energy Nuclear Interaction eXperiment, or PHENIX. Later he managed construction of quark-related calorimeters for sPHENIX, a radical makeover of PHENIX. He earned his doctorate from Yale University.
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