Theorists find new electromagnetic effects that shift the spin-dependent coupling of the nucleon to the weak force and point out the implications for new physics in beta decay. Outside atomic nuclei, ...

A new result from the Q-weak experiment at the Department of Energy’s Thomas Jefferson National Accelerator Facility provides a precision test of the weak force, one of four fundamental forces in ...

Physicists have found that an elementary particle called the W boson appears to be 0.1 percent too heavy—a tiny discrepancy that could foreshadow a huge shift in fundamental physics. The measurement, ...

In nuclear beta decay an up quark ‘u’ in a proton converts into an up down quark ‘d,’ turning the proton into a neutron and emitting a positron and a neutrino. This work affects interpretation of beta ...

Scientists have made a particle physics discovery that they say could mean nothing less than the upheaval of our entire model of the building blocks of the universe—if their results can be ...

A spinning neutron disintegrates into a proton, electron, and antineutrino when a down quark in the neutron emits a W boson and converts into an up quark. The exchange of quanta of light (γ) among ...