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quasar987
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In weak desintegrations, the isospin is not necessarily conserved. But is the total angular momentum J=L+S+I always conserved?
Yes. The total angular momentum conservation is twin to energy and linear momentum conservation, and that has never been observed to be broken.In weak desintegrations, the isospin is not necessarily conserved. But is the total angular momentum J=L+S+I always conserved?
So the isospin is an angular momentum in the sense
He does !?Cohen-Tanoudji defines angular momentum as any operator which satisfies the commutation relation [itex] [J_i,J_j]=\hbar\epsilon_{ijk}J_k[/itex].
So, what you are doing has no link with G-symmetry ? You were mentionning weak interaction. It maximally violates parity, so combining parity and isospin reverse, you often get (almost) conserved quatities...But it doesn't add to L and S.
The J=1/2 is wrong. Ispin has nothing to do with angular momentum.This is not the answer I was hoping for!
I have this problem here that roughly says "a B particle disintegrate into a pi+ and a pi-". So I said "B has isospin 1/2, spin 0 and (there exists a ref. frame where B has) L=0. So that's J=1/2 for B. I know that the state ket for pipi must be symmetrical (2 indistinguishable bosons). And now I know that J total must be conserved.
Can someone show me the reasoning behind how to extract the nature (symmetric or antisymmetric) of [itex]|\pi^{+}\pi^{-}>[/itex] given the above information.
First sentence of p.646: This is why we shall adopt a more general view and define and angular momentum [itex]\mathbf{J}[/itex] as any set of three observables which satisfies: [itex] [J_i,J_j]=i\hbar\epsilon_{ijk}J_k[/itex]He does !?![]()
I don't know what G-symmetry is; this exercise is in the context of the Wigner-Eckart theorem in an ordinary undergrad QM class.So, what you are doing has no link with G-symmetry ? You were mentionning weak interaction. It maximally violates parity, so combining parity and isospin reverse, you often get (almost) conserved quatities...
First sentence of p.646: This is why we shall adopt a more general view and define and angular momentum ...
First sentence of p.646: This is why we shall adopt a more general view and define and angular momentum [itex]\mathbf{J}[/itex] as any set of three observables which satisfies: [itex] [J_i,J_j]=i\hbar\epsilon_{ijk}J_k[/itex]