{"id":25238,"date":"2024-09-17T16:57:40","date_gmt":"2024-09-17T11:12:40","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=25238"},"modified":"2024-09-17T16:57:44","modified_gmt":"2024-09-17T11:12:44","slug":"cms-experiment-at-cern-weighs-in-on-the-w-boson-mass","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/cms-experiment-at-cern-weighs-in-on-the-w-boson-mass\/","title":{"rendered":"CMS experiment at CERN weighs in on the W boson mass"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

Geneva\u2014<\/strong> The\u00a0CMS<\/a>\u00a0experiment at CERN is the latest to weigh in on the mass of the\u00a0W boson<\/a>\u00a0\u2013 an elementary particle that, along with the\u00a0Z boson<\/a>,\u00a0mediates the weak force, which is responsible for a form of radioactivity and initiates the nuclear fusion reaction that powers the Sun.<\/p>\n\n\n\n

At a\u00a0seminar<\/a>\u00a0held at CERN today, the CMS collaboration reported how it has analyzed proton-proton collision data from the second run of the\u00a0Large Hadron Collider<\/a>,\u00a0the Laboratory\u2019s flagship particle accelerator, to make its first mass measurement of this fundamental particle.<\/p>\n\n\n\n

The\u00a0result<\/a>\u00a0is the most precise measurement of the W mass made so far at the LHC. It is in line with the prediction from the\u00a0Standard Model<\/a>\u00a0of particle physics and with all previous measurements, except the measurement from the CDF experiment at the former proton\u2013antiproton\u00a0Tevatron<\/a>\u00a0collider at Fermilab.<\/p>\n\n\n\n

In the Standard Model, the W mass is closely related to the strength of the interaction unifying the electromagnetic and weak forces and to the masses of the\u00a0Higgs boson<\/a>\u00a0and the\u00a0top quark<\/a>, which constrain its value to 80353 million electronvolts (MeV) within an uncertainty of 6 MeV.<\/p>\n\n\n\n

Measuring the W boson mass with high precision therefore makes it possible to test whether or not these properties all align in a way that is consistent with the Standard Model. If they don\u2019t, the cause could be new physics phenomena such as new particles or interactions.<\/p>\n\n\n\n

Since its discovery at CERN about 40 years ago<\/a>, the W boson has had its mass measured ever more precisely by several collider experiments, at CERN and elsewhere. In 2022, a surprisingly high value of its mass measured by the CDF experiment plunged the particle into a \u201cmidlife crisis<\/a>\u201d. The CDF W boson mass<\/a>, 80433.5 MeV with an uncertainty of 9.4 MeV, differed significantly from the Standard Model prediction and from the other experimental results, calling for more studies.<\/p>\n\n\n\n

In 2023, the\u00a0ATLAS<\/a>\u00a0collaboration, which provided its first W boson mass measurement in 2017,\u00a0released<\/a>\u00a0an improved measurement based on a reanalysis of proton-proton collision data from the first run of the LHC. This improved result,\u00a080366.5 MeV with an uncertainty of 15.9 MeV<\/a>, lined up with all previous measurements except the CDF measurement, which remains the most precise to date, with a precision of 0.01%.<\/p>\n\n\n\n

The\u00a0CMS experiment has now contributed to this global endeavor with its first W boson mass measurement. The keenly anticipated result, 80360.2 with an uncertainty of 9.9 MeV, has a precision comparable to that of the CDF measurement and is in line with all previous measurements except the CDF result.<\/p>\n\n\n\n

\u201cThe wait for the CMS result is now over. After carefully\u00a0analyzing\u00a0data collected in 2016 and going through all the cross-checks, the CMS W mass result is ready,\u201d says outgoing CMS spokesperson Patricia McBride. \u201cThis analysis is the first attempt to measure the W mass in the harsh collision environment of the second running period of the LHC. And all the hard work from the team has resulted in an extremely precise W mass measurement and the most precise measurement at the LHC.\u201d<\/p>\n\n\n\n

\u201cW mass measurements are very challenging, involving delicate measurements and theoretical modeling of the production of the W boson and its decay into a lepton (here, a muon) and a neutrino that escapes detection,\u201d explains incoming CMS spokesperson Gautier Hamel de Monchenault. \u201cBy exploiting the ability of the CMS detector to measure muons with high precision and using the latest and most advanced theoretical ingredients, some of which were tested by a cross-checking analysis, we attained this record level of precision.\u201d<\/p>\n\n\n\n

The result showcases once again the exceptional performances of the LHC and its detectors, which continue to push the precision frontier and put the Standard Model and its extensions to ever more stringent tests. Further data from the ongoing third run of the collider and its upgrade, the\u00a0High-Luminosity LHC<\/a>, is poised to push this frontier further.<\/p>\n","protected":false},"excerpt":{"rendered":"

The\u00a0CMS\u00a0experiment at CERN is the latest to weigh in on the mass of the\u00a0W boson\u00a0\u2013 an elementary particle that, along with the\u00a0Z boson,\u00a0mediates the weak force<\/p>\n","protected":false},"author":2,"featured_media":25239,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,121],"tags":[],"class_list":["post-25238","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","category-physics"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",1100,619,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-200x200.jpg",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-675x380.jpg",675,380,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-768x432.jpg",750,422,true],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-675x380.jpg",675,380,true],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",1100,619,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",1100,619,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",1100,619,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-870x570.jpg",870,570,true],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-600x619.jpg",600,619,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-600x600.jpg",600,600,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-760x490.jpg",760,490,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-550x360.jpg",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern-95x65.jpg",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",640,360,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",96,54,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2024\/09\/cms-w-boson-mas-cern.jpg",150,84,false]},"author_info":{"info":["RevoScience"]},"category_info":"Research<\/a> Physics<\/a>","tag_info":"Physics","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/25238","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=25238"}],"version-history":[{"count":1,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/25238\/revisions"}],"predecessor-version":[{"id":25240,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/25238\/revisions\/25240"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/25239"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=25238"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=25238"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=25238"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}