From Science, March 6, 2017: For more than a decade, multiple experiments have found an unexpected excess in the number of high-energy antielectrons, or positrons, in space. A team led by Fermilab’s Dan Hooper has shown that pulsars, not dark matter annihilation, can indeed produce most or all of the excess.

Antimatter in the universe is extremely rare; the universe is made pretty much entirely out of matter. DZero digs deeper into a previous, unusual result measuring the difference between matter and antimatter.

Scientists of the DZero collaboration at the Department of Energy’s Fermi National Accelerator Laboratory announced Friday, May 14, that they have found evidence for significant violation of matter-antimatter symmetry in the behavior of particles containing bottom quarks beyond what is expected in the current theory, the Standard Model of particle physics.