Gauge Bosons Speed

[EdEarl]

Do all the Gauge Bosons move at the speed of light, or only the photon?

[swansont]

The other ones in the standard model have mass.

[EdEarl]

Would gravity waves propagate slower than the speed of light, since Higgs bosons are massive?

[Enthalpy]

The (up to now massless) graviton is the mediator, not the Brout-Englert-Higgs boson - which, by the way, gives the mass of some particles only.

[ajb]

Do all the Gauge Bosons move at the speed of light, or only the photon?

Gauge bosons that are asymptotically free (correspond to incoming or outgoing states in a scattering experiment) are constrained to obey the usual rules of relativistic particle mechanics. For example, if they have mass they must travel at speeds less than c and at c is they are massless.

 

However, this is not true of virtual particles, that is particles that appear in the internal loops of Feynman diagrams. However, it turns out that this does not effect causality.

 

So the answer to your question depends on what you are asking about exactly.

Edited November 20, 2013 by ajb

[EdEarl]

tyvm everyone

Edited November 20, 2013 by EdEarl

[timo]

Do all the Gauge Bosons move at the speed of light, or only the photon? Would gravity waves propagate slower than the speed of light.

The graviton would, if it existed. The gluon would, if it existed as a free particle. The gauge bosons of SU(2) and U(1) would if they weren't affected by the Higgs Mechanism. And ironically, being unstable the W and the Z boson probably won't have much of a definable speed unless they move close to the speed of light (because otherwise they decay very quickly, which may well be before they passed a distance that significantly exceeds the size of their wave packet).

 

The (up to now massless) graviton is the mediator, not the Brout-Englert-Higgs boson - which, by the way, gives the mass of some particles only.

To be precise, the Higgs boson does not give mass to any particle at all. It's the interaction with the part of the Higgs field that is not the Higgs boson that causes mass terms for elementary particles.

 

However, this is not true of virtual particles, that is particles that appear in the internal loops of Feynman diagrams. However, it turns out that this does not effect causality.

It's somewhat debatable to what extend you can define a sensible "speed" for virtual particles. Or call them particles in the first place. Just taking equations from wave dynamics, plugging them on momentum eigenstates and calling that "velocity" and "particle", respectively, appears a bit too shortcut to me. Not only in the particular case of interacting states, where calling the solutions of the non-interacting case "particles" seems particularly dubious to me.