Gary Taubes
The strong force that holds quarks together to make up protons and neutrons has long defied theorists' calculations. Lately, however, with the help of years of supercomputer calculations, they have predicted the properties of hypothetical offspring of the strong force called glueballs--collections of gluons, the particles that transmit the strong force. Glimpses of glueballs in accelerator data are now confirming the predictions and telling theorists that their grasp of the force is sound.