CMS candidate collision event for a W boson decaying into a muon (red line) and a neutrino that escapes detection (pink arrow). (Image: CMS/CERN)
Remember when scientists from the CMS experiment at CERN – using a method developed by DESY – put forward the most precise measurement of the mass of the W boson? The are proud to report that this high-precision measurement was published in Nature today.
„“The value of 80360.2 +- 9.9 MeV, measured with unprecedented precision at the LHC, aligns with the Standard Model and pushes the precision frontier to the next level, strengthening our understanding of electroweak interactions and setting a new benchmark for future measurements,” explains DESY scientist Katerina Lipka, whose team was involved in the measurement.
Knowing the mass of the W boson with very high precision is an key factor for checking whether theoretical predictions hold. And if they don’t it helps scientists spot deviations from them fast and reliably. Experimental and theoretical particle physicists at DESY played a major role in this challenging analysis.
Read more about the role of the W boson and the role DESY plays in the international endeavour:
News story by DESY (September 2024)
Press release by CERN
Original publication:
The CMS Collaboration. High-precision measurement of the W boson mass with the CMS experiment. Nature 652, 321–327 (2026). DOI: 10.1038/s41586-026-10168-5
