Fermions are just one of the basic categories of particles, and almost all of them are Dirac, meaning they have a complementary and distinctive antiparticle—think electron and positron.

For the first time, scientists have observed a collection of particles, also known as a quasiparticle, that's massless when moving one direction but has mass in the other direction. The ...

The scientists compared the behavior of the particles within the material to a train traveling on a network of tracks. In some directions, this train can move extremely fast, as if it had no weight.

Representative illustration. A semi-Dirac fermion has mass when it’s moving in one particular direction but not in a perpendicular direction. | Photo Credit: Dima Solomin ...

Had this move happened weeks ago – before Unity went on record to deny it was looking to sell up – the word “acquisition” would have probably featured prominently in any editorials or columns that ...