## What is the annihilation of positron and an electron?

In particle physics, annihilation is the process that occurs when a subatomic particle collides with its respective antiparticle to produce other particles, such as an electron colliding with a positron to produce two photons.

What is the equation for annihilation?

E = mc2
The amount of energy (E) produced by annihilation is equal to the mass (m) that disappears multiplied by the square of the speed of light in a vacuum (c)—i.e., E = mc2.

### What happens when positron and electron collide?

When they meet, the positron and the electron, which are Antiparticles of each other, destroy themselves mutually, they annihilate. Two annihilation gamma with equal energy are also emitted back to back.

What is annihilation in radiology?

Annihilation in general refers to the transition of a particle and its antiparticle by collision into something different, depending on their energies and based on the conservation of energy and momentum. Two gamma rays of 0.511 MeV energy, assuming very low-energy particles, are emitted perpendicular to each other.

#### Can a positron annihilate an electron?

When an electron and a positron collide, they annihilate, resulting in the complete conversion of their rest mass to pure energy (according to the E=mc2 formula) in the form of two oppositely directed 0.511 MeV gamma rays (photons).

Can an electron turn into a positron?

No, electron does not turn into positron due to change of the reference frame. The wave function sign changes, but it is not the electron charge.

## Why are 2 photons produced in annihilation?

Annihilation occurs when a particle and a corresponding antiparticle meet and their mass is converted into radiation energy. Two photons are produced in the process (as a single photon only would take away momentum which isn’t allowed, as no outside forces act).

Can an electron become a positron?

When an electron is subject to an interaction that changes the rotational direction of its circumferential B-field from left-handed to right-handed, it becomes a positron.

### What kind of photon is produced in annihilation?

Annihilation is assumed to be a “complete obliteration of an object”. When an electron and a positron (the electron’s antimatter counterpart) collide, they annihilate and disappear, giving off two gamma rays in the process. The particles appear to have vanished and all energy is transferred to the gamma rays (photons).

How do you make an electron positron pair?

In the pair production process, an incident gamma ray of sufficiently high energy is annihilated in the Coulomb field of a nearby charged particle, resulting in the creation of an electron–positron pair.

#### Do quarks and antiquarks annihilate?

Pair annihilation processes usually result in the production of two photons. For example, a quark and its respective antiquark can annihilate and produce two Z-bosons. But, an up quark and an anti-down quark can annihilate and produce a W+-boson and a Z-boson.

Is positron a stable particle?

Stable in a vacuum, positrons quickly react with the electrons of ordinary matter by annihilation to produce gamma radiation.