Anti Proton vs Neutron annihilation

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SUMMARY

The discussion centers on the interactions between anti protons and neutrons, specifically addressing whether annihilation occurs and the resulting particles. An anti proton consists of 2 anti up quarks and 1 anti down quark. While anti protons do not annihilate with neutrons to produce photons, they can lead to hadronization, resulting in the production of pions. At low energy, neutron-antiproton collisions typically yield pions, while higher energy collisions may produce baryons along with additional pions.

PREREQUISITES
  • Understanding of quark composition, specifically "up" and "down" quarks.
  • Knowledge of particle physics concepts such as annihilation and hadronization.
  • Familiarity with Quantum Chromodynamics (QCD) and its role in particle interactions.
  • Basic comprehension of particle collision outcomes, including baryons and pions.
NEXT STEPS
  • Research "Quantum Chromodynamics (QCD) and hadronization" to understand particle interactions further.
  • Study "pion production in particle collisions" to explore outcomes of neutron-antiproton interactions.
  • Examine "Feynman diagrams for particle interactions" to visualize annihilation processes.
  • Learn about "high-energy particle collisions and baryon production" to grasp advanced collision outcomes.
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Particle physicists, students of quantum mechanics, and anyone interested in the fundamental interactions of subatomic particles will benefit from this discussion.

Stephanus
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Dear PF Forum,
Just out of curiosity.
What happens when an anti proton hits a 'normal' neutron?
According to this:
https://en.wikipedia.org/wiki/Proton
https://en.wikipedia.org/wiki/Neutron
A proton has 2 up quarks, 1 down quark
A neutron has 1 up quark, 2 down quarks.

1. Does anti proton has 2 anti up quarks and 1 anti down quark
2. Can antiproton be annihilated with 'normal' neutron?
3. Can anti up quark be annihilated with 'normal' up quark?
4. So if anti proton can be annihilated with neutron what would the result? 1 anti up quark and 1 'normal' down quark?

Thank you very much. Just out of curiosity
 
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Stephanus said:
1. Does anti proton has 2 anti up quarks and 1 anti down quark
yes. But these are called valance quarks. There is also a "sea of virtual quarks" and the gluons.

Stephanus said:
2. Can antiproton be annihilated with 'normal' neutron?
annihilation in the sense of "disappearing" and giving photons, no. The proton would not be annihilated with an antiproton either. They can lead to hadronization however; eg pions.

Stephanus said:
3. Can anti up quark be annihilated with 'normal' up quark?
yes. For example the \pi^0 \rightarrow \gamma \gamma is such an annihilation.

Stephanus said:
4. So if anti proton can be annihilated with neutron what would the result? 1 anti up quark and 1 'normal' down quark?
there can be many ways for them to interact (especially with their gluons)
 
Thanks ChrisVer for the answer
ChrisVer said:
Stephanus said:
2. Can antiproton be annihilated with 'normal' neutron?
annihilation in the sense of "disappearing" and giving photons, no. The proton would not be annihilated with an antiproton either. They can lead to hadronization however; eg pions.
But, please did you say the proton would not be annihilated with an antiproton either?Would you elaborate a little? Thanks.
 
Stephanus said:
But, please did you say the proton would not be annihilated with an antiproton either?Would you elaborate a little? Thanks.

Simply put they will result to hadronization... if you want, you can consider it as annihilation but it's not that they give photons, they give hadrons [because QCD dominates]
One example I found fast by google:
http://teachers.web.cern.ch/teachers/archiv/HST2002/feynman/exampl14.gif
p\bar{p} \rightarrow n \bar{n}
 
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The most likely result of a proton-antiproton collision at low energy is an annihilation-like reaction which produces a few pions and destroys proton and antiproton. As charge is conserved, the number of negative and positive pions is the same.
The most likely result of a neutron-antiproton collision at low energy is an annihilation-like reaction which produces a few pions and destroys neutron and antiproton. As charge is conserved, the number of negative pions will be 1 larger than the number of positive pions.

Very similar reactions.
At higher energy, it is more likely that the collision still leads to baryons (can be the original ones, but different ones are frequent as well) plus additional pions.
 
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