= Massive-fermion chiral weight at fixed helicity
{title2=$w_L(h=+1/2)=(1-\beta)/2$}
For a positive-energy <Dirac spinor> normalized to unit probability and with positive <helicity>, the left-chiral component has squared weight $(1-\beta)/2$, where $\beta=|\mathbf p|/E$ in <natural units>. Its right-chiral weight is $(1+\beta)/2$; for negative helicity the two are exchanged. In an ultrarelativistic positive-helicity particle, the left-chiral amplitude is suppressed by a mass-to-energy ratio.
Back to article page
