BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:HEP Colloquia 2025 DTSTART:20250507T123000Z DTEND:20250507T133000Z DTSTAMP:20260514T225000Z UID:indico-event-46852@agenda.infn.it CONTACT:hepcolloquia@ca.infn.it DESCRIPTION:Speakers: Marco Cipriani (Università & INFN Pisa)\n\nPrecise measurement of the W boson mass with the CMS experiment\nThe W boson mass (mW) is a fundamental parameter of the standard model (SM) of particle phy sics. The SM predicts mW as a function of other precisely measured paramet ers of the theory\, and a global fit to these parameters yields mW = 80353 ± 6 MeV\, which corresponds to a precision better than 10-4.Observing a deviation from this prediction would be a striking indirect evidence of ne w physics beyond the SM. Therefore\, achieving a similar uncertainty in a direct measurement of mW is crucial to test the internal consistency of th e theory.The current experimental average\, which combines different measu rements from multiple experiments at the LEP\, Tevatron\, and LHC collider s\, gives mW = 80369.2 ± 13.3 MeV\, in fair agreement with the SM. Howeve r\, few years ago the CDF Collaboration reported a new measurement with an uncertainty of 9.4 MeV\, which is currently the most precise from a singl e experiment but also in strong tension with the SM prediction\, hinting t o possible effects from new physics.New determinations of mW targeting the same precision as the SM prediction are thus mandatory to solve this puzz le. This talk presents the first measurement of mW carried out by the CMS Collaboration at the LHC\, using data collected at 13 TeV.Innovative exper imental techniques and a novel approach to deal with theoretical uncertain ties have been adopted\, resulting in the most precise determination of mW at the LHC\, with an uncertainty close to the one of the CDF result.\n\nh ttps://agenda.infn.it/event/46852/ LOCATION:Sala Consiliare (Department of Physics) URL:https://agenda.infn.it/event/46852/ END:VEVENT END:VCALENDAR