Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

W and Z bosons

  1. May 19, 2010 #1
    What affect does gravity have on W and Z bosons?
     
  2. jcsd
  3. May 19, 2010 #2
    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?
     
  4. May 19, 2010 #3

    bapowell

    User Avatar
    Science Advisor

    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.
     
  5. May 19, 2010 #4

    bapowell

    User Avatar
    Science Advisor

    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.
     
  6. May 19, 2010 #5
    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?
     
  7. May 19, 2010 #6

    bapowell

    User Avatar
    Science Advisor

    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.
     
  8. May 19, 2010 #7
    So would this force exchange still occur in beta decay and would this force then be transferred to particles involved, like the electron neutrino?
     
  9. May 19, 2010 #8
    Yes .
     
  10. May 19, 2010 #9
    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?
     
  11. May 19, 2010 #10

    bapowell

    User Avatar
    Science Advisor

    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.
     
  12. May 19, 2010 #11
    The question would be, could photons transfer force to charged particles without the W boson?
     
  13. May 19, 2010 #12

    bapowell

    User Avatar
    Science Advisor

    Yes. The theory of quantum electrodynamics (QED) governs all electromagnetic interactions. No W bosons needed.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook