Understand Eta Particle Decay into 3 Pions

  • Thread starter Thread starter eendavid
  • Start date Start date
  • Tags Tags
    Decay Pion
eendavid
Messages
17
Reaction score
0
1. The statement, all variables and given/known data
I am studying the decay of the \eta-particle. Povh et Al, 'Particles and nuclei' say that a decay into 3 pions is not possible via the strong interaction. "For reasons of symmetry 3 pions (isospin equals 1) can not couple to zero isospin." This explains the long lifetime of the eta-particle. I do not understand this.


Homework Equations


Denote by D^{(j)} the non-reducible representations of a rotation in isospin space, then D^{(1)}\otimes D^{(1)}=D^{(2)}\oplusD^{(1)}\oplusD^{(0)}


3. The problem
As
D^{(1)}\otimes D^{(1)}\otimes D^{(1)}= ...\oplus D^{(1)}\otimes D^{(1)}\oplus..., their are D^{(0)} components in the 3 pion system. Am I making a misinterpretation somewhere?
 
Physics news on Phys.org
For the purpose of archiving, here's the answer: the decay violates conservation of G-parity, which is conserved in the strong interaction.
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
Back
Top