Why doesn't a dineutron system form a bound state?

Click For Summary

Discussion Overview

The discussion centers on the reasons why a dineutron system does not form a bound state, contrasting it with the binding of a neutron-proton pair. Participants explore the implications of spin and isospin symmetry in nucleon interactions, as well as the binding energy of different nucleon configurations.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions why two neutrons with opposite spins do not form a bound state, while a neutron and proton do.
  • Another participant inquires about the relative binding energy per nucleon in different configurations of neutron-proton pairs.
  • A third participant notes that any bound state of two neutrons would decay to deuterium (1H2) through the weak force.
  • One participant suggests that the lack of a bound state for two neutrons is due to the spin and isospin symmetry properties of the nucleon-nucleon force.
  • A participant references previous discussions on the topic, indicating that it has been explored multiple times in the forum.

Areas of Agreement / Disagreement

Participants express differing views on the mechanisms preventing dineutron binding, with no consensus reached on the reasons or implications of these interactions.

Contextual Notes

Participants mention the need to consider spin and isospin symmetry properties, but the discussion does not resolve the implications of these factors or the specifics of the nucleon-nucleon force.

zahero_2007
Messages
75
Reaction score
0
Why doesn't a dineutron system form a bound state?

Why doesn't 2 neutrons with one spin up and the other spin down form a bound state but a neutron and proton with both spin up or down form a bound state
 
Physics news on Phys.org


Another question , Is the binding energy per nucleon (assuming A is small enough) stronger for a p-n nucleus with one spin up and the other spin down than a p-n nucleus with both spin up or down?
 


Of the possible bound states for two nucleons, the ground state is 1H2, so a state of two neutrons would decay to this via the weak force.
 


Ok , but Why doesn't the 2 neutrons form a ground state?
 


Because of the spin and isospin symmetry properties of the nucleon-nucleon force.

If I remember correctly wer had this discussion here a coupleof times; please search for "dineutron" or something like that.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 10 ·
Replies
10
Views
5K