K+/- Decay: Angular Momentum Explained

[Broken]

So, the common leptonic decay channels for the K^{+/-} is the two quarks annhilating into a W^{+/-} which then decays into whatever electron/muon neutrino pair. What's confusing me is that the K^{+/-} is J=0 but the intermediate W is J=1. Is the answer to give the W one unit of orbital angular momentum such that there is a state of 0 total angular momentum?

 

[Vanadium 50]

A real W has a well-defined spin. But this is a virtual W.

 

[malawi_glenn]

I thought only E and p was concerned in virutal verticies. Then one can argue that neither electric charge or anything else must be conserved in verticies, if one allows angular momentum to be violated aswell.

The thing I think is that the W is emitted in a relative angular momentum L = 1, then L = 1 and J = 1 can add to 0.

Just what I have thought of.

 

[nrqed]

I thought only E and p was concerned in virutal verticies. Then one can argue that neither electric charge or anything else must be conserved in verticies, if one allows angular momentum to be violated aswell.

I agree. Virtual particles are off-shell (P^2 is not equal to m^2) but four-momentum is conserved at the vertices as well as angular momentum, charge and any other conserved quantum numbers.

 

[malawi_glenn]

Also remember that the K meson is not an elementary particle, it is a composite system of a quark and an antiquark