# Which particles have helicity?

I know electrons have helicity but can particles which are not fundamental i.e.protons have helicity?

Helicity of a particle is defined to be the projection of its spin vector $\mathbf{s}$ along the direction of its impulse $\mathbf{p}$:
$$H = \frac{\mathbf{s}\cdot\mathbf{p}}{||\mathbf{s}\cdot \mathbf{p}||}$$
• Neutrino helicity is $-1$
So every particle with spin $\neq 0$ and/or $m \neq 0$ has helicity.