Pions are some of matter’s simplest particles. They’re built from the same building blocks as protons and neutrons, smaller particles known as quarks. While a proton is made from three quarks, only ...

A result 20 years in the making: Most precise measurement yet of the neutral pion confirms predictions of a fundamental symmetry DOE/Thomas Jefferson National Accelerator Facility Nuclear physicists ...

Symmetry breaking is often seen as a bad thing. The greater the asymmetry in our faces, so we are told, the less attractive we appear to others. However, if nature did not break a subtle symmetry ...

Pionic helium In this experiment, a pion – shown here with one orange and one blue particle representing its quark and anti-quark – replaces one of the two electrons in the helium atom. This new ...