Proton-Antiproton Annihilation

  • Thread starter Skatch
  • Start date
  • #1
Skatch
18
0

Homework Statement



A proton and antiproton at rest in an S-state annihilate to produce [tex]\pi[/tex]0[tex]\pi[/tex]0 pairs. Show
that this reaction cannot be a strong interaction.

Homework Equations



I interpret this problem as:

p + p_bar -> [tex]\pi[/tex]0 + [tex]\pi[/tex]0

The Attempt at a Solution



If this were a strong interaction, Parity should be conserved, yes? I think that in the annihilation
described above, parity is not being conserved.


But really, my first question is, am I interpreting it correctly? Is the annihiliation producing [tex]\pi[/tex]0 + [tex]\pi[/tex]0?
Or is it producing [tex]\pi[/tex]0 + [tex]\pi[/tex]0 + [tex]\pi[/tex]0 + [tex]\pi[/tex]0? Not sure what they mean by "[tex]\pi[/tex]0[tex]\pi[/tex]0 pairs".


Then my next question is, what is the Parity of p_bar?
 
Last edited:

Answers and Replies

  • #2
Skatch
18
0
Okay, so I think I've come to the conclusion that the Parity of the antiproton is -1.
I read that, in general, P(fermion * antifermion) = -1, and since proton's parity is +1, I'm
going to conclude that parity of the antiproton is -1.

Okay, so total parity on the left hand side of the equation is 0.

But I still don't know if I'm interpreting the problem correctly. Is the annihilation producing:

[tex]\pi[/tex]0 + [tex]\pi[/tex]0 ?

[tex]\pi[/tex]0 + [tex]\pi[/tex]0 + [tex]\pi[/tex]0 + [tex]\pi[/tex]0 ?

[tex]\pi[/tex]0[tex]\pi[/tex]0 ?

[tex]\pi[/tex]0[tex]\pi[/tex]0 + [tex]\pi[/tex]0[tex]\pi[/tex]0 ?

Pardon the ignorance here. I'm taking this Nuclear Physics class despite not meeting some
of the pre-reqs. I'm a math major that was just interested in the material, so I'm a bit
behind.

Thanks for any help.
 

Suggested for: Proton-Antiproton Annihilation

Replies
5
Views
285
Replies
13
Views
1K
  • Last Post
Replies
16
Views
2K
Replies
10
Views
812
Replies
3
Views
507
Replies
1
Views
427
Replies
3
Views
622
Replies
1
Views
929
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
3
Views
2K
Top