Quasiparticles

Scientists have accidentally discovered a particle that has mass when traveling in one direction, but no mass while moving in a different direction. Known as semi-Dirac fermions, particles with this bizarre behavior were first predicted 16 years ago.

While studying a material that could help unlock the secrets of superconductors, scientists have accidentally discovered a “demon” particle that was first theorized almost 70 years ago, but had never been experimentally confirmed.