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Scalar interactions amd chirality

  1. Oct 26, 2015 #1
    why do scalar interactions(for example the higgs vev or its components) reverse the chirality of the interacting particle?? i think this is the key for understanding the mass generation of fermions, but i cant think of a logical reason of the reversed chirality.
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  3. Oct 26, 2015 #2

    Vanadium 50

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    I would say it's the exact opposite - because they are scalars, they don't care about chirality and thus can couple left-handed and right-handed fields.
  4. Oct 26, 2015 #3
    ok thanks i understand it sort of(and sorry for posting this as a intermediate level thread. ishouldve posted it as basic...). so scalar interactions preserve angular momentum(i guess helicity... right?) but does not 'think about' chirality and therefore they can couple left-right chiral particles which leads to fermion mass...right?
  5. Oct 26, 2015 #4


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    Yes. Since the scalar has zero angular momentum, in order for the interaction term with fermions to be Lorentz invariant, it is necessary to couple a left chiral field to (the conjugate of) a right chiral one. You can compare this to the kinetic terms, where, because of the appearance of the 4-vector derivative (behaves like spin 1), it is necessary to couple a chiral field to a field of the same chirality.
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