Helicity is an extrinsic physical property related to the alignment of spin and momentum; chirality is related to weak interactions. Chirality is more akin to electric charge or strong color charge than it is …

Polarisation, spin, helicity, chirality and parity keep confusing me. They seem to be related, but exactly how they are related is unclear to me. Can someone maybe give a short overview about what ...

Because that's the way it is: the photon doesn't have spin, it only has helicity. Essentially, massive particles have spin, massless ones have helicity.

Jan 22, 2018 · Then boost it to the opposite infinitesimal momentum so it has the opposite helicity. The helicity is then a step function of the momentum. What is the value at the midpoint of a step function, …

Aug 15, 2021 · Definition of the helicity operator Ask Question Asked 4 years, 4 months ago Modified 4 years, 4 months ago

But helicity's current is always conserved in time (this fact doesn't depend on mass; this is expressed in $ (1)$). You also may build the expression for helicity's weak current and see that it is different from …

Jul 2, 2016 · . For photon we use helicity, not spin, because massless representations of the Poincare group can't be characterized by the spin.

Apr 19, 2022 · I previously understood helicity to simply be the projection of spin onto momentum - how does this change sign from a mass change, or is this definition of helicity simplified/incomplete? Apr …

Aug 16, 2017 · Thus, such particles have two helicity states. Wigner's classification in this form, while explaining why all massless particles have two helicity states, does not guarantee that all quantized …

@PhysiXxx The helicity eigenvalue in contrast to that of the spin projection indicates the identity of the particle. For example a photon with a positive helicity is a different particle from a photon with a …