W boson

A more precise result can expose a new problem or resolve an apparent discrepancy. That is the case with the Muon g-2 experiment with the most precise measurement of the muon and with the mass of the W boson.

Recently, scientists have determined the mass of the W boson by analyzing more than 1 billion proton-colliding events produced by the LHC at CERN. The precision of the new measurement is on par with a previous measurement made in 2022 by the CDF at Fermilab.

A 2022 measurement of the W boson’s mass by the CDF experiment at the Fermilab, while the most precise measurement, differed from the Standard Model prediction. Now, a new calculation of the W boson particle by the CMS collaboration agrees with the Standard Model.

In 2022, the CDF experiment at Fermilab measured the W boson mass and found a challenge in the predictions of physics. However, the LHC measurement of the mass of the W boson found the exact expected value. What now?

Two experiments measuring the W boson have two different results. The lead analyzer of the CDF experiment discusses the differing results and what’s next for the W boson measurements.

Following nearly a decade of analysis, the CMS experiment has found that the W boson’s mass aligns perfectly with Standard Model predictions with remarkable accuracy.

Physicists on the CMS experiment announce the most elaborate mass measurement of a particle that is notoriously difficult to study and has captivated the physics community for decades.

The ATLAS collaboration measured the W-boson width at the LHC for the first time. The W-boson width had previously been measured at CERN’s LEP collider and Fermilab’s Tevatron collider. This is the most precise measurement to date made by a single experiment, and—while a bit larger—it is consistent with the Standard-Model prediction to within 2.5 standard deviations.

From New Scientist, Dec. 16, 2022: This year was another busy year in science and technology and New Scientist news editors’ have chosen some of the biggest scientific developments, discoveries and events in 2022. Included in this year’s selections is the April 2022 announcement of the mass of the W boson that used Fermilab’s Tevatron.

From Science News, August 15, 2022: W bosons are particles that transmit the weak force, which is responsible for certain types of radioactive decay. Last April, Fermilab researchers reported the W boson was more massive than predicted, hinting that something may be amiss with the standard model. Now a team of scientists with ATLAS at the LHC are reporting rare boson triplets which continues to test the standard model for any cracks.