This year's Breakthrough Prize in Fundamental Physics was awarded to three generations of the Muon g-2 experiment: the CERN experiment in the 1970s, the Brookhaven experiment in 2000, and finally the Fermilab experiment, which published its final results in June 2025, helping settle what will remain the most precise measurement of the muon's magnetic moment for years to come.
The Breakthrough Prize, established by science and technology visionaries, including the founders of Meta and Google, is widely considered one of the most prestigious prizes in science.
The selection process is separate from the founders (Zuckerberg, Milner, etc.), who provide the funding but leave the scientific decision entirely to the Selection Committee, composed of several Nobel laureates (t'Hooft, Reiss, Perlmutter, etc.) and theoretical and experimental physicists recognized for their fundamental contributions to the development of physics.
The Italian team, consisting of researchers from the INFN Divisions of Naples, Pisa, Rome Tor Vergata, and Trieste, the Frascati National Laboratories, and the CNR-INO in Pisa, has actively participated in the Muon g-2 experiment at Fermilab since its inception. The INFN team contributed significantly to the success of the measurement by designing and building both a complex laser system for absolute calibration of the calorimeters used in the energy measurements, and a high-sensitivity optical magnetometer for measuring magnetic transients. The use of these systems significantly reduced the overall uncertainty in the measurement of the muon magnetic anomaly. Italian researchers also contributed massively to the significant data analysis effort required to obtain the final result and held senior positions in the organizational chart, including the roles of co-Spokespersons for the experiment, first with Graziano Venanzoni and then with Marco Incagli, both of INFN Pisa.
Researchers from the INFN Division in Trieste and the INFN Group in Udine developed essential parts of the systems deployed at Fermilab, also contributing to management with Giovanni Cantatore, who served as National INFN Responsible.
News:
https://www.infn.it/fisica-fondamentale-il-breakthrough-prize-2026-alle-collaborazioni-muon-g-2-con-un-ruolo-chiave-dellinfn/
https://www.nature.com/articles/d41586-026-01014-9
https://home.cern/news/press-release/cern/muon-g-2-experiment-pioneers-win-breakthrough-prize-fundamental-physics
https://breakthroughprize.org/News/98
