April 19, 2014

Collider reveals sharp change from ‘quark soup’ to atoms

Using the atom-smasher at the U.S. Department of Energy’s Brookhaven National Laboratory and its ability to scan to lower collision energies, scientists have observed a sharp phase transition — different from the smooth change in the early universe — from a “hot soup” of quarks and gluons, into the protons, neutrons and electrons in atoms that are the building blocks of matter.