Penn ATLAS Shares 2025 Breakthrough Prize in Fundamental Physics

Researchers from the ATLAS Collaboration at CERN, which includes physicists in the Penn ATLAS group, received the 2025 Breakthrough Prize in Fundamental Physics for their work studying high-energy collisions from the Large Hadron Collider (LHC). ATLAS shares the $3 million award with three other experiments at CERN—CMS, ALICE, and LHCb—recognizing the efforts of some 13,500 scientists worldwide.

More than two dozen members make up the Penn ATLAS team, which includes Joseph Kroll, Robert I. Williams Endowed Term Professor of Physics and Astronomy; Evelyn Thomson, Professor of Physics and Astronomy; Elliot Lipeles, Professor of Physics and Astronomy; Dylan Rankin, Assistant Professor of Physics and Astronomy; and Brig Williams, Emeritus Professor of Physics and Astronomy, as well as numerous PhD students, postdocs, and technical staff.

“To do this great science you need a really big team,” Lipeles says. “The LHC is the most complicated piece of equipment ever built. I don’t think anything even comes close. Which means in the end, all the different bits and pieces have different groups responsible for them.”

Decades of Work

The Breakthrough Prize, one of science’s highest honors, is annually awarded in the categories of Life Sciences, Mathematics, and Fundamental Physics. Presented as an Academy Award–style honor for scientists, the prize—and the event around it—frequently attracts big names from Hollywood and Silicon Valley. But for all the glitz and glamor, the award itself honors intensive, painstaking work.

At Penn, that has meant a variety of efforts. The team played a leading role in the discovery of the Higgs boson particle 12 years ago and continues to make precision measurements of the particle’s properties. One of the most intriguing ongoing searches entails looking for signs that the Higgs boson can decay invisibly to dark matter. “Searches are also underway for signs of new particles that are partners to the Higgs boson,” Thomson says.

The pivotal role played by this world-leading group in the discovery of the Higgs boson is fundamental science at its absolute best.

In addition, the research team is confirming and investigating facets of the Standard Model, an extraordinarily successful model in particle physics that can be used to describe elementary particles and their interactions in a range of environments, from proton collisions in labs to the early universe.

Yet scientists understand that the model is incomplete. To that end, Lipeles, Kroll, and Thomson are all working on aspects of something called supersymmetry, which tries to fill in some of the Standard Model’s holes. “Supersymmetry could offer explanations for the nature of dark matter, why the Higgs boson has the mass it does, even whether we’re in a stable or unstable universe,” Kroll says.

Then there’s the extensive data coming out of this project. Rankin, for example, uses machine learning to analyze whether the Standard Model’s predictions match the outcomes. “We have the Standard Model, which we use to predict what should happen when we collide protons. We can look at the data and say, is this what actually happens?” Rankin explains. “The signals we are looking for are hidden in this enormous volume of data, and machine learning is allowing us to look in places and in ways that we simply wouldn’t have been able to look otherwise.”

What Comes Next

Experimentation at the LHC is far from complete. Currently the research is delivering data in a five-year period referred to as “Run 3,” which ends in 2026. (The Higgs boson was discovered in the analysis of data from Run 1, and the prize just awarded was for analysis of data collected in Run 2, the period from 2015 to 2018.) In 2030, the LHC will begin a decade-long high-luminosity stage (HL-LHC), which should deliver 10 times more data than previous runs.

As the LHC evolves, so does the ATLAS detector. The Penn ATLAS group has an internationally renowned team of instrumentation specialists that includes four physicists and electrical engineers who design high-speed advanced electronics. For the original ATLAS detector, Penn designed custom readout electronics for the Transition Radiation Tracker, a tool that reconstructs the trajectory of ionization trails left behind after high-energy collisions of fast-moving particles. For the upgraded HL-LHC version, the Penn team has designed and tested advanced readout electronics for a new silicon strip tracker with 60 million channels of electronics. “Taking experimental data for decades requires a giant effort,” Thomson says.

Despite what’s still to come, receiving the accolade now is an affirmation of all that the team has already achieved. “I am thrilled that literally decades of basic research and technical work by our ATLAS faculty have been recognized,” says Arjun Yodh, James M. Skinner Professor of Science and chair of the Department of Physics and Astronomy. “The Standard Model is considered by many to be the most quantitatively successful physical theory every devised. Along with their PhD students, postdocs, and technical staff, our ATLAS faculty have played a leadership role in elucidating its critical features and in exploring the new physics beyond it.”

“I am delighted to see Penn’s ATLAS group recognized in such a high-profile manner,” adds Mark Trodden, Associate Dean for the Natural Sciences, Fay R. and Eugene L. Langberg Professor of Physics, and co-director of Penn’s Center for Particle Cosmology. “The pivotal role played by this world-leading group in the discovery of the Higgs boson is fundamental science at its absolute best.”

The Breakthrough Prize is the world’s largest science prize. The money, $1 million of which will go to ATLAS specifically, will fund scholarships for PhD students. 

Previous awardees from Penn Arts & Sciences include Charles Kane, Christopher H. Browne Distinguished Professor of Physics, and Eugene Mele, Christopher H. Browne Distinguished Professor of Physics, in 2019, for their discovery of a new class of materials known as topological insulators. And in 2016, Eugene Beier, Emeritus Professor of Physics and Astronomy; Joshua Klein, Edmund J. and Louise W. Kahn Endowed Term Professor of Physics and Astronomy; Christopher Mauger, Associate Professor of Physics and Astronomy; and others were part of two teams that won for their work on neutrino oscillations.