The W boson might not be heavier than expected after all
The particle’s mass is an important test of the standard model of particle physics
![A photo from the ATLAS experiment at CERN's Large Hadron Collider.](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2023/03/032923_JR_wboson_feat.jpg?fit=1030%2C580&ssl=1)
A fresh analysis of W boson measurements from the ATLAS experiment (pictured) at CERN’s Large Hadron Collider is in close agreement with theory and at odds with a heavy W boson mass announced last year.
Maximilien Brice/CERN