# Eta -> gamma gamma

## Main Question or Discussion Point

eta --> gamma gamma

Could someone help me on this. Iso spin is not conserved in EM interaction. How can we say isospin is not conserved in the 'eta -> 2 gamma' decay.The eta has I =1 and I3 =0 and for the gamma I = 0 ,1. Thanks a lot

Related High Energy, Nuclear, Particle Physics News on Phys.org
Meir Achuz
Homework Helper
Gold Member

The gamma has no defined Ispin since Ispin is not conserved if a gamma is involved.
The eta has I=0, not 1.

The gamma has no defined Ispin since Ispin is not conserved if a gamma is involved.
The eta has I=0, not 1.
Thanks for the reply, that's my typing mistake, I=0 for eta.
OK. LHS I = 0 RHS I = not defined
So, isospin is not conserved. Is that the way to explain non conservation of isospin
thanks