W and Z bosons

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What affect does gravity have on W and Z bosons?

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Can electromagnetic force interact with the W and Z bosons given the photon can exchange momentum to mass? The W and Z bosons both have mass so can a force be exchanged?

bapowell

Since the W and Z bosons each have nonzero energy density, they interact gravitationally. Gravity has the same effect on everything that has stress-energy (anything with energy density and the ability to exert pressure and/or transfer momentum) -- this is a result of the equivalence principle on which general relativity is based.

bapowell

Only particles with electric charge interact with photons -- mass has nothing to do with it. In the standard model of particle physics, it's possible to have interactions of the form:

(W+) + (W-) ----> photon + Z

but this is not the same as the photon 'interacting' with the Z. There is no direct interaction (for example, there is no coupling term like ZZA, where A = photon) that is allowed in the standard model. This is because the Z is neutral, and A only couples to charged particles.

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If the interaction can involve the W+ and W-.this must affect the interaction W bosons have with other particles. Does the W boson curve in magnetic fields?

bapowell

Sure. The W bosons are electrically charged particles. As such, they couple directly to the photon (there are AW+W- terms in the standard model). A W boson will trace out a curved path in a magnetic field just as an electron would.

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So would this force exchange still occur in beta decay and would this force then be transferred to particles involved, like the electron neutrino?

ansgar

Yes .

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Is the W boson the link in electromagnetic interaction? Are fermions influenced by electromagnetic force through W boson interaction? If not how can we differentiate between charged fermions and fermion boson interaction in magnetic fields?

bapowell

No. Photons are the mediators of the electromagnetic force. The W/Z bosons mediate the weak force. There is no way to distinguish a charged boson from a charged fermion by measuring its path through a magnetic field. The curvature of the path of a charged particle through a magnetic field is useful for determining the particle's mass.

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The question would be, could photons transfer force to charged particles without the W boson?

bapowell

Yes. The theory of quantum electrodynamics (QED) governs all electromagnetic interactions. No W bosons needed.