What is a photon in QFT?

The photon (Greek: φῶς, phōs, light) is a type of elementary particle. It is the quantum of the electromagnetic field including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Lewis popularized the term photon for these energy units.

How does a photon travel?

As shown by Maxwell, photons are just electric fields traveling through space. Photons have no charge, no resting mass, and travel at the speed of light. Photons are emitted by the action of charged particles, although they can be emitted by other methods including radioactive decay.

How does light energy move from one place to another?

Light travels as a wave. But unlike sound waves or water waves, it does not need any matter or material to carry its energy along. This means that light can travel through a vacuum? It speeds through the vacuum of space at 186,400 miles (300,000 km) per second.

How does a photon carry charge?

Photons are elementary excitations of the quantum electromagnetic field. They do not carry charge.

What is an example of a QFT field?

For example, the EM field consists of electric and magnetic fields that are described by the QFT equivalent of Maxwell’s equations. Quanta. The fields of QFT exist in units called quanta . Each quantum is a holistic piece of field that lives a life and dies a death of its own.

What is the difference between photons and Quanta?

The photon is a quantum of the EM field and protons and neutrons are quanta of the baryon field. Quanta may be free and travel through space, or they may be bound, like an electron in an atom. If a quantum is absorbed or changes its spin state, it does so as a unit.

What is the energy of photon energy of electron and positron?

• Since the electron and positron each have an energy equivalence of 511 keV, the incoming photon must have an energy of at least 1022 keV for pair production to take place. • Any additional photon energy above 1022 keV is given to the positron and the electron as kinetic energy. are not necessarily the same.

What is an example of quantum electrodynamics?

As an example, quantum electrodynamics contains a Dirac field ψ representing the electron field and a vector field Aμ representing the electromagnetic field ( photon field). (Despite its name, the quantum electromagnetic “field” actually corresponds to the classical electromagnetic four-potential,…