W bosons mediate the nuclear weak interaction, one of the fundamental forces in physics. Because the Standard Model (SM) of particle physics places tight constraints on the mass of the W boson and its relation to the masses of the top quark and the Higgs boson, measuring these masses puts the SM to the test. The Collider Detector at Fermilab (CDF) Collaboration now reports a precise measurement of the W boson mass extracted from data taken at the Tevatron particle accelerator. Surprisingly, the researchers found that the mass of the W boson was significantly higher than the SM predicts, with a discrepancy of 7 standard deviations.
The measurement has been published in Science, 7 Apr 2022, Vol 376, Issue 6589 pp. 170-176 DOI: 10.1126/science.abk1781
Professor Lucio Cerrito of the Department of Physics is a member of the CDF Collaboration, and the experiment has received funding from the Italian National Institute of Nuclear Physics (INFN).