Search Results

The two notions are only the same for massless particles - for which then helicity is also frame-invariant since massless particle have no rest frame. … Its helicity flips, sure, but its chirality - the thing the weak interaction cares about - doesn't. …

Helicity is different from angular momentum because the angular momentum algebra is the Lie algebra of the massive little group $\mathrm{SO}(3)$, while helicity is for massless particles and hence must … So how does this helicity relate to $4\pi$ rotations? …

The article you link is choosing to use non-standard terminology to explain how the weak force can couple to particles with a certain handedness but not others. I do something similar with "electron-1 …

There are two of them that are interchanged by parity transformations, so the "usual" massless particle gets a two-dimensional "helicity representation". …

On the level of the field strength tensor $F$, duality is the map $F\mapsto {\star}F$, where ${\star}$ is the Hodge dual. Maxwell's equations in vacuum are $$ \mathrm{d}F = 0 \quad \text{and} \quad \m …

Helicity is the projection of spin onto momentum. … If by "total helicity" you mean the projection of the total spin onto the total momentum, then this is impossible to compute from the individual helicities (take the extreme case where each individual …

The unitary representations are labeled by the mass and spin (for massive states) and helicity (for massless states), but not by anything that would lend itself to be interpreted as chirality that would … The available operator is helicity (and other spin components, of course), not chirality. …

The states with circular polarization in your basis are called helicity because they are eigenstates of the helicity operator. … For more on helicity for photons, see e.g. this answer or this answer of mine. …

They have helicity, which is the value of the projection of the spin operator onto the momentum operator. … And that's it - massless particles of helicity $h$ have the $h\oplus -h$ representation on their space of states, not a spin representation of $\mathrm{SO}(3)$. …

Another one of these issues where careless terminology is our downfall. Indeed, on the level of the Dirac equation, such a thing as a "left-handed electron" does not exist. Every pure electron and ev …

Helicity is the projection of the spin vector upon momentum. … It is to be noted that, for massless fermions, the chiral subspaces are precisely the eigenspaces of helicity. …