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Charged pions $\pi^\pm$ decay via an intermediate $W$ to (e.g.) a lepton-neutrino pair.

The pions being scalar (spin-0) particles and the intermediate $W$ having spin 1, how is spin conserved in this interaction?

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  • $\begingroup$ Aren't the spins of the lepton and the neutrino both $\frac{1}{2}$? $\endgroup$ – Kyle Kanos Jul 10 '13 at 15:47
  • $\begingroup$ Yes, they are. But my question is not about spin conservation between initial and final state, but in between. $\endgroup$ – fuenfundachtzig Jul 10 '13 at 17:55
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    $\begingroup$ The same question has been asked here: physics.stackexchange.com/questions/89684/… $\endgroup$ – fuenfundachtzig Feb 3 '14 at 14:29