CMS observed the simultaneous production of four top quarks, one of the rarest physics processes ever observed at the LHC, opening the door to detailed searches for physics beyond the Standard Model (SM).   Ever since its discovery at the Tevatron, i…

For over two millennia, people have wondered about the diversity of the material world, asking questions like “what are things made of?”. In the early decades of the 20th century we figured out that all things are composed of electrons, protons, and…

Dark matter is mysterious. In some ways, we know a lot about it, including its average density in the universe and upper limits for how strongly the dark matter particles might interact with each other or with “normal” Standard Model particles. In ot…