From Wired, April 5, 2017: For some reason, more matter formed than antimatter just after the Big Bang, and physicists don’t know why. “It’s one of the very biggest mysteries in the universe,” says physicist Don Lincoln of Fermilab.
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.
From New Scientist, July 4, 2016: A new result from the NOvA and T2K experiments sheds light on the matter/antimatter imbalance in the early universe.
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.