Large Hadron Collider Pauses Protons; Looks Ahead to Lead

The Large Hadron Collider has completed many successful months of colliding protons (hydrogen ions) at record-breaking energies and now begins four weeks of colliding much more massive lead ions, giving access to different physical phenomena. Berkeley Lab hosts U.S. participation in the ALICE experiment, designed specifically to study the heavy-ion collisions that give rise to a unique phase of matter, the quark-gluon plasma. Berkeley Lab is also a major participant in the ATLAS experiment, one of the other LHC experiments that will study lead-lead collisions.