The quarks that make up the nuclei of all atoms around us are known to "mix": the different types of quark occasionally change into one another. The amounts in which these processes happen are not ...

All good things come in threes. The Standard Model of particle physics takes this motto to heart: it contains three so-called generations of elementary particles. Take the quarks as an example. In ...

A view inside a proton moving at nearly the speed of light toward the viewer with its spin pointing horizontally shows differences in the spatial distributions of the momentum of up (left) and down ...