A Weyl fermions are a type of massless particle that are the soloution to Paul Dirac’s equations relating matter and antimatter. They are often described as chiral which simply means you get two different forms of them that are reflections of each other, like your hands which would also be called chiral. They have yet to be observed but definitely exist although there is some debate about whether they are analogous to a quantum field or not. To theoretically observe these particles we need to design what is known as an ideal Weyl semimetal where the structure is a metallic crystalline lattice and all excitation in the system are Weyl fermions (the equivalent of electrons due to their chirality). And now in an alloy of Mercury and Tellurium it has been observed that at least four nodes (groups of the same chiral spin) have formed and the surface is covered in an effect known as Fermi arcs which are simply to theoretical and beyond my current understanding. These are signs of a perfect Weyl semimetal and this discovery could easily lead to direct observations of these elusive particles.