A collaboration of nuclear theorists has used supercomputers to predict the spatial distributions of charges, momentum, and other properties of 'up' and 'down' quarks within protons. The calculations ...

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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 ...

Evidence of a particle made up of four tightly bound quarks tests physicists’ understanding of the force that holds protons and neutrons together. The particles in a hadron are bound tightly together ...