Question about particle reaction

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    Particle Reaction
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Discussion Overview

The discussion centers around the feasibility of the particle reaction ##N+\nu_e \rightarrow e^{-}+P##, exploring whether it is possible within the framework of particle physics, particularly in the context of weak interactions and conservation laws.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that the reaction is possible because charge, baryon, lepton, and fermion numbers are conserved.
  • Others affirm that this reaction is a known process in charged-current neutrino scattering, which is relevant for neutrino detectors.
  • One participant notes that for free neutrons, natural decay is more likely unless there is a very high neutrino flux.
  • A participant expresses confusion regarding the weak interaction and its implications for charge and parity symmetry, questioning the possibility of the corresponding antiparticle reaction.
  • Another participant suggests that both charge inversion and parity operation must be considered for the reaction to be possible under weak interactions.
  • Some participants argue that the reaction is impossible due to the transformation of a right-handed neutrino into a right-handed antineutrino, which they claim does not exist in the Standard Model.
  • A later reply clarifies that antiparticles are typically considered as CP-conjugates rather than just C-conjugates.
  • One participant mentions that C and CP violations do not render the process completely impossible, suggesting that it may still occur under certain conditions.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the possibility of the reaction. While some affirm its feasibility, others contend that it is impossible due to symmetry violations and the nature of neutrinos and antineutrinos.

Contextual Notes

There are unresolved aspects regarding the implications of charge and parity violations, as well as the specific conditions under which the reaction may or may not occur. The discussion reflects varying levels of understanding and assumptions about particle interactions.

Clear Mind
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It's an easy question, let's consider this reaction:
##N+\nu_e \rightarrow e^{-}+P##
Is this reaction possible? If is not, what does violate?

(I think is possible because charge is conserved, baryon, lepton and fermion numbers are conserved. But I'm not totally sure)
 
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Yes, this is charged-current neutrino scattering. It's one of the processes that neutrino detectors look for.
 
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Yes.

However, note that for free neutrons, it is much more likely that the neutrons will decay naturally unless you have an outrageously high neutrino flux.
 
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Thank you all!
dukwon said:
It's one of the processes that neutrino detectors look for.
I suppose that the cross section it's really small ...
 
Clear Mind said:
Thank you all!

I suppose that the cross section it's really small ...

This is why neutrino detectors are really big ... :)
 
From a few day I've started to study particle physics, so I'm still a little bit confused ... I was wondering:
##N+\nu_e \rightarrow e^{-}+P##
it's a weak interaction, so it should violate c-symmetry, thus:
##\bar{N}+\bar{\nu_e} \rightarrow e^{+}+\bar{P}##
shouldn't be possible ...
I'm a little puzzled :(
 
It is possible if you make both a charge inversion and a parity operation, since the weak force couples to left-handed fermions and right-handed antifermions.

Usually when we talk about an antiparticle it's the CP-conjugate rather than the C-conjugate.
 
yes it is impossible, because you turned a right-handed neutrino into a right-handed antineutrino ... which doesn't exist [in SM]
 
ChrisVer said:
yes it is impossible, because you turned a right-handed neutrino into a right-handed antineutrino ... which doesn't exist [in SM]

It's the other way round. Antineutrinos have to be right-handed in the Standard Model.
 
  • #10
ChrisVer said:
yes it is impossible, because you turned a right-handed neutrino into a right-handed antineutrino ... which doesn't exist [in SM]
Right! i was considering only charge, baryon, lepton and fermion numbers but not the parity :s
 
  • #11
dukwon said:
It's the other way round. Antineutrinos have to be right-handed in the Standard Model.

OMG! indeed! Well I'm always forgetting the a-priori left and right... [except for when I write the doublets]...
 
  • #12
C and CP violation do not mean the process is completely impossible. It can have a different dependence on the relative angles (P violation), or occur a bit more or less frequent even with an additional P transformation (CP violation), but it is still possible.
 

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