MajoranaSpinor

A Majorana spinor is a type of elementary particle described by a specific mathematical formulation in quantum field theory. Unlike Dirac spinors, which describe particles that are distinct from their antiparticles, Majorana spinors represent particles that are their own antiparticles. This means that if a particle is a Majorana spinor, its antiparticle is identical to itself in all properties, including charge, mass, and spin.

The concept of Majorana fermions was first introduced by Ettore Majorana in 1937. The mathematical representation of a Majorana spinor is a four-component complex column vector that satisfies the Majorana condition, which essentially states that the spinor is equal to its charge conjugate. This condition imposes a constraint on the structure of the spinor.

The existence of Majorana fermions has significant implications for particle physics. For instance, if neutrinos are Majorana particles, this could provide a natural explanation for their small masses through the seesaw mechanism. While the Standard Model of particle physics describes fundamental particles as Dirac fermions, there is ongoing experimental effort to determine whether neutrinos are indeed Majorana particles. Experiments searching for neutrinoless double beta decay are a key way to test this hypothesis, as this process can only occur if neutrinos are Majorana fermions. The discovery of a Majorana fermion would represent a major breakthrough in our understanding of fundamental physics.