Why must an electron-positron collision produce gamma rays?

In summary, the frequency of photons emitted in a collision depends on the spin and energy states of the initial particles and is governed by energy and momentum conservation. The collision may also result in other products, such as neutrino/antineutrino pairs or gravitons, with small branching fractions. Decays of Positronium result in even lower branching fractions for electron neutrino + antineutrino pairs.
  • #1
animagaletix
1
0
Or, more specifically, what determinates the frequency of the photons emitted by a such a collision. I know that the number of photons produced depends on the spin and energy states of the initial particles.
 
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  • #2
Energy and momentum conservation.

The collision does not have to produce gamma rays, other products are possible if the energy is sufficient, and elastic scattering is always possible.
 
  • #3
If the particles are going at relatively low speeds, then the annihilation will result in a pair of photons at 511 kev.
 
  • #4
mfb said:
Energy and momentum conservation.
And spin and parity.
Which does not determine branching fractions between equally allowed processes.
mfb said:
The collision does not have to produce gamma rays, other products are possible if the energy is sufficient,
There is always enough energy to produce neutrino/antineutrino pairs, of three flavour options, or gravitons.
 
  • #5
With tiny branching fractions, yes (especially for the gravitons).
Decays of Positronium - 10-18 for electron neutrino + antineutrino, even lower for the other flavors.
 

What is an electron-positron collision?

An electron-positron collision is a type of subatomic particle interaction where an electron and a positron (the antimatter counterpart of an electron) come into contact and annihilate each other, releasing energy in the form of gamma rays.

Why must an electron-positron collision produce gamma rays?

According to the laws of physics, when an electron and a positron collide, they can only produce energy in the form of gamma rays. This is due to the conservation of energy and momentum, where the total energy and momentum before and after the collision must remain the same.

How are gamma rays produced in an electron-positron collision?

During an electron-positron collision, the particles annihilate each other and their mass is converted into pure energy in accordance with Einstein's famous equation E=mc². This energy is then released in the form of gamma rays, which are high-energy photons.

What is the significance of studying electron-positron collisions and gamma rays?

Electron-positron collisions and the resulting gamma rays are important for understanding the fundamental properties of matter and energy. They are also used in many fields of science, such as particle physics, astrophysics, and medical imaging.

Can electron-positron collisions be observed in nature?

While electron-positron collisions do occur naturally, they are rare and difficult to observe. They are more commonly created in controlled environments, such as particle accelerators, where scientists can study their properties and behavior.

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