Pair Production: Creating Matter from Light

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Discussion Overview

The discussion revolves around the concept of pair production, specifically the creation of matter from electromagnetic waves. Participants explore the conditions under which particles, such as electrons, positrons, and quarks, can be produced from photons, as well as the implications of neutrino production in this context.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant notes that photons with energy exceeding 1.022 MeV can create electron-positron pairs and questions whether photons with energy exceeding the rest mass of quarks could produce quark pairs.
  • Another participant clarifies that particles must be created in pairs and points out that down quarks are not antiparticles of up quarks, emphasizing that each quark flavor has its own antiparticle. They also mention that quarks cannot exist independently, suggesting the creation of pions instead.
  • A different participant raises the question of whether neutrinos, having near-zero mass, could be produced in significant numbers before the electron-positron pair is formed.
  • In response, it is stated that pair production is an electromagnetic interaction and that neutrinos do not participate in this interaction. A later edit mentions that while photo-production of neutrinos is theoretically possible, it requires a strong magnetic field, implying that neutrinos would not be produced in abundance alongside pair production.

Areas of Agreement / Disagreement

Participants express differing views on the production of quarks and neutrinos, indicating that multiple competing perspectives exist regarding the mechanisms and conditions for pair production.

Contextual Notes

There are limitations regarding the assumptions about particle interactions and the conditions necessary for the production of specific particles, such as quarks and neutrinos, which remain unresolved in the discussion.

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Pair production interests me - create matter from electromagnetic waves.

So far I have read that a Positron-Electron pair can be created by photons having energy exceeding twice the rest energy (m * c ^ 2) of an electron (1.022 MeV).

So, if you have photons exceeding the energy of an up and down quark, (Max 6.8 MeV), you would be creating up and down quarks in addition to electrons and positrons?
 
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Well, except for two things. First, you can only create particles and antiparticles in pairs. And a down quark is not the antiparticle of an up quark. Each "flavor" of quark has its own antiparticle. Second, you need to create particles that can exist on their own, and a quark cannot. For example you could create a π+ π- pair, 140 Mev for each pion.
 
Since neutrinos have a near zero mass, would there be many of them created then before getting anywhere near the electron-positron pair?
 
Pair-production is an electromagnetic interaction - and neutrinos don't experience that one.
Prev discussion.

[edit]
Appears you can get photo-production of neutrinos in theory, but that needs a strong magnetic field so you would not expect a flurry of neutrinos showing up ahead of the usual pair-production.
 
Last edited:

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