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Scalar field and spin 1/2 field

  1. Aug 21, 2007 #1
    are bosons represented by a scalar field and fermions represented by a spin 1/2 field or how does it work?
     
  2. jcsd
  3. Aug 21, 2007 #2

    strangerep

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    Bosons have integer spin (0,1,2...). Fermions have half-integer spin (1/2, 3/2, ...)
     
  4. Aug 22, 2007 #3
    does that mean a scalar field is a spin zero field or is it an integer spin field?
     
  5. Aug 22, 2007 #4
    A scalar field is a spin zero field. For spin one you'd need a vector field and for spin two you'd need a second rank tensor field.
     
  6. Aug 22, 2007 #5
    what about a spin 1/2 or spin 3/2?
     
  7. Aug 22, 2007 #6
    A spin-1/2 particle is described using a Lorentz/Dirac Spinor Field. There are no “fundamental” spin-3/2 particles so the field that would describe it isn’t used that often. However if you know representation theory you can easily see what the field’s properties are like.

    Also there are difficulties in taking spin-3/2 theories further than second order in perturbation theory, which is one of the reasons for the field formalism.
     
  8. Aug 22, 2007 #7
    is there a different propagator for each spin field?
     
  9. Aug 22, 2007 #8
    Yes, there is a different propagator for each field as they have different Hamiltonians. There is also a different Feynman propagator for each free particle species of a given spin.*

    *Obviously there are also different propagators for interacting theories, but their analytic forms aren’t known.
     
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