Quantum Field Theory says that an electron should not have mass. However, we know that it does. It has finite quantum states, which evolve over time, and it doesn’t travel at the speed light. An unusual interaction that involves parity violation is what gives electrons mass.
An electron is a fermion, a particle that obeys fermi–dirac statistics. It has an intrinsic property called Spin. The value of this spin property is 12
Or -12
. Mind you, this spin is quite different to the traditional notion of spin. The electron has a property called “chirality”, which can either be left-handed, or right-handed. An electron’s chirality is determined by its spin in the same direction it moves as its motion. It is left-handed if it spins in the opposite direction to its motion. This property, called chirality is important for weak interactions.
The weak force, out of all the forces, is the only one that cares about a particle’s spin. It also cares about its chirality and if it’s an antiparticle. This phenomenon is known as parity violation. The weak force is the only one that can exhibit this. This is why a left-handed electron exhibits weak hypercharge, an additional property that is associated with particles that interact the weak force. It is unique in that the electron does not possess weak hypercharge if it has a right handed chirality.
Additionally, the electron’s spin continues to “oscillate”, or, in simpler terms, its quantum state constantly evolves over time between two possible states ( 12).
And -12
This evolution is described in the Schrodinger equation. This oscillation between having weak hypercharge and not raises a question. What is the source and destination of this charge when an electron’s chirality changes? The Higgs field is the answer. The Higgs field is non-zero in space. This contrasts with other QFT fields which hover over zero. This unlimited supply of weakly charged electrons can be described as the Higgs field. An electron takes this charge and gives it back whenever its chirality changes.
Its mass is due to its interaction with the Higgs Field.