Scalar interactions amd chirality

[kimcj]

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 can't think of a logical reason of the reversed chirality.

 

[Vanadium 50]

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.

 

[kimcj]

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.

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?

 

[fzero]

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.