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

The neutrino and electroweak transformations

  1. Apr 15, 2012 #1
    Hi, quick question.

    "In electroweak theory, the neutrino belongs to an SU(2) doublet"

    So, does the neutrino belong to an SU(2)xU(1) (electroweak) doublet or just SU(2)?

    Last edited: Apr 15, 2012
  2. jcsd
  3. Apr 15, 2012 #2


    User Avatar
    Science Advisor

    The left-handed neutrino and left-handed electron form an electroweak SU(2)xU(1) doublet. The right-handed electron forms an electroweak singlet. The right-handed neutrino, if it exists, also forms a singlet.
  4. Apr 15, 2012 #3
    It's possible to speak of a particle's transformation properties under SU(2) and U(1) separately. Under SU(2) transformations the neutrino transforms as part of a doublet. Under U(1) transformations the neutrino picks up a phase proportional to its hypercharge. So I think it's most correct to say "SU(2)" double instead of "SU(2) x U(1)" doublet.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook