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Feynman rules for electroweak multiplets

  1. Oct 11, 2011 #1
    Can someone refer me to Feynman rules for electroweak interactions in the general case of SU(2) multiplets of weak isospin n and weak hypercharge Y interacting with EW gauge bosons?

    I can only find the standard rules for SU(2) doublet electron - neutrino.

    Thanks!
     
  2. jcsd
  3. Oct 11, 2011 #2

    Bill_K

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    Science Advisor

    The interaction term in the standard model Lagrangian is

    Lγμ(i∂μ - g/2 τ·Wμ - g'/2 Y Bμ)L + Rγμ(i∂μ - g'/2 Y Bμ)R

    where L and R are left- and right-handed fermions and τ are the three Pauli matrices. So all you would have to do for an isospin n fermion is to replace τ by the three SU(2) matrices for isospin n, which are given by

    τ±|n m> = √(n∓m)(n±m+1) |n m±1>
    τ3|n m> = m |n m>
     
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