The most precise measurement of the mass of the W boson has been obtained at CERN, a particle discovered by Carlo Rubbia in 1983 for which the Italian physicist won the Nobel Prize together with the Dutchman Simon van der Meer. The result, as the National Institute of Nuclear Physics noted in a note, is an important new confirmation of the validity of the Standard Model, the reference theory of physics.
The result, long awaited by the international scientific community, was obtained by the CMS experiment, carried out using the Large Hadron Collider (LHC). The new value of 80,360.2 MeV was presented by the CMS Scientific Collaboration, with an important Italian contribution, during a symposium held on 17 September at CERN.
“The precision achieved now was unthinkable when the LHC and CMS were designed,” emphasizes Giacomo Sguazzoni, Infn researcher and national director of the CMS experiment. “This procedure is the result of many years of work, during which we encountered and solved many experimental problems,” adds Lorenzo Bianchini, from the University of Pisa, linked to Infn and coordinator of the project dedicated to this procedure.
The result was obtained “using only one-tenth of the run2 data,” Bianchini said, referring to the LHC’s period of activity between 2015 and 2018.
Since its discovery, the W boson has been measured with ever-increasing precision. The result now presented by CMS is consistent with theoretical predictions and with all previous measurements, except for the one obtained in 2022 at Fermilab, in the United States, which measured a surprisingly high value for the mass of the W boson. At the moment, it has not been confirmed by any other experiments. “This new measurement shows that no new phenomena or new particles are needed to explain nature,” says Stefania De Curtis, director of the Galileo Galilei Institute for Infinite Sciences.
Reproduction © Copyright ANSA
“Internet trailblazer. Travelaholic. Passionate social media evangelist. Tv advocate.”
