CMS Measures Higgs Boson Mass at 125.065 GeV
The Compact Muon Solenoid experiment reports the most precise single-experiment Higgs boson mass measurement to date.
Updated on Nov. 2, 2026 in Physics
The CMS experiment at CERN's Large Hadron Collider has determined the Higgs boson mass to be 125.065 GeV, with an uncertainty of 88 MeV. The result combines proton-proton collision data at 7, 8 and 13 TeV from two decay channels.
Why it matters
The Higgs boson mass is a free parameter of the Standard Model that must be measured experimentally, so greater precision sharpens a key input to particle physics theory. The result also lays groundwork for a future combination with ATLAS measurements.
The measurement combines H → γγ and H → ZZ → 4l decay channels using collision data at 7, 8 and 13 TeV, with a mass precision of 0.07% and an 88 MeV uncertainty. The combined CMS-ATLAS value that could further refine this figure has not yet been reported.
The players
CMS Collaboration
The Compact Muon Solenoid collaboration is one of the two large general-purpose experiments at CERN's Large Hadron Collider that independently study the Higgs boson.
CERN
The European Organization for Nuclear Research operates the Large Hadron Collider and publishes the results of its experiments.
The details
The measurement required detector calibration, detailed process modelling, and evaluation of uncertainty sources. The H → ZZ → 4l channel selects events yielding four electrons, muons, or one pair of each, while the H → γγ channel reconstructs the Higgs decay into two photons.
Timeline
Collision data was collected at 7, 8 and 13 TeV collision energies; exact dates of publication were not specified in the source.
Zoom In
Establishing a more precise Higgs boson mass sharpens the reference value on which future studies of the particle's properties depend. Combining CMS results with the ATLAS experiment at the Large Hadron Collider could further refine that value and support deeper investigations of the Higgs boson.
The precision of the Higgs boson mass shapes the calculations physicists use to test the Standard Model, though it does not directly affect everyday technology. Its practical impact lies in refining the theoretical framework that underpins future particle physics research.
The takeaway
The Higgs boson mass is a fundamental parameter that had to be measured rather than predicted, and each gain in precision narrows the uncertainty in Standard Model calculations. Combining results across independent experiments is a key method for steadily sharpening that knowledge.
Further reading
Explore more in our Physics section for context on the Standard Model and particle measurements.
Source note: This article includes information reported by Cms.
