Powerful supercomputer simulations of high-energy collisions between atomic cores provide new insights about the complex structure of a superhot fluid called the quark-gluon plasma.
Hydrogen is a neutral atom. Its single electron orbits a single proton, and the net effect is no electrical charge. But what about hydrogen’s antimatter counterpart, antihydrogen? Made of a positron that orbits an antiproton, the antihydrogen atom should be neutral too. Various results have indicated as much, but because the charge of antiatoms is
Last month, ATLAS, the particle detector that helped find the Higg’s boson, got an upgrade. Scientists at the Large Hadron Collider at CERN added a new set of sensors, called the Insertable b-Layer, or IBL, into the core of the detector. The IBL will be closer to particle collisions than previous sensors and contain more,
Theory and observations support the view that antimatter experiences gravity just as ordinary matter does, but the evidence so far has been indirect. Indeed, some theorists speculate that antimatter is antigravitational, that it may fall “up” instead of “down.” Led by Berkeley Lab physicists, the ALPHA Collaboration at CERN has made direct measurements of the gravitational mass of atoms of antihydrogen, testing how they fall and in what direction.
CERN’s Large Hadron Collider collides protons most of the year but switches to massive lead nuclei for a month. Collisions of these heavy ions reproduce the quark-gluon plasma that filled the universe millionths of a second after the big bang. Much of the program for quark-gluon plasma studies is shaped by theoretical and experimental contributions from Berkeley Lab’s Nuclear Science Division, as shown by results from ALICE and other experiments during the LHC’s first lead-lead run just concluded.
Atoms of antimatter have been trapped and stored for the first time by the ALPHA collaboration, an international team of scientists working at CERN in Switzerland. Berkeley Lab researchers made key contributions to the effort, including the design of the trap’s crucial component—an octupole magnet—and computer simulations needed to identify real antihydrogen annihilation events against a noisy background.