When the universe was only millionths of a second old, quarks moved freely in a hot, dense soup of quarks and gluons, but soon protons and neutrons and other forms of ordinary matter “froze out” of this quark-matter soup. Now scientists have compared quantum theory and data from the STAR experiment for the first time to map out the energies and temperatures where ordinary matter melts and the quark-gluon plasma freezes.

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.

A team of scientists working at the Advanced Light Source’s femtosecond beamline 6.0.2 have taken the first step toward controlling how matter interacts with x-rays, shaping x-ray pulses with other x-ray pulses, and eventually directing the paths chemical reactions can take.

The ALICE detector at CERN’s Large Hadron Collider will study the fireballs that result when energetic lead ions collide, recreating conditions like those when the universe was just a millionth of a second old. An ALICE instrument called EMCal will signal the most interesting events. Designed by an international collaboration spearheaded by scientists and engineers at Berkeley Lab and other U.S. institutions, EMCal is now on its way to completion.