A tiny subatomic particle called the W boson may be heavier than scientists have previously thought and it could shake up physics’ grand theory of everything

Scientists at the U.S. Fermi National Accelerator Laboratory spent 10 years analyzing mass measurements of the W boson, a lesser-known “sister particle” of the Higgs Boson that plays a role in radioactive decay. They found the particle is somewhat heavier than physics theories expected. And that, the scientists said in a statement, is quite a big deal, as it is at odds with the so-called Standard Model, a fundamental physics theory describing how the world on the microscale fits together.