Talk:Helicity basis

Bad dimensions

The dimensions in the equation

\xi _{+1}({\vec {p}})={\sqrt {\frac {2|{\vec {p}}|}{|{\vec {p}}|+p_{z}}}}{\begin{pmatrix}|{\vec {p}}|+p_{z}\\p_{x}+ip_{y}\end{pmatrix}}={\begin{pmatrix}\cos {\frac {\theta }{2}}\\e^{i\phi }\sin {\frac {\theta }{2}}\end{pmatrix}}\,

are definitely wrong as cos and sin are dimensionless. — Preceding unsigned comment added by Hardi27 (talk • contribs) 09:53, 30 September 2012 (UTC)[reply]

It appears to have been fixed at some point. 67.198.37.16 (talk) 03:09, 1 December 2020 (UTC)[reply]

Notation

It is not clear from the article what $\chi _{\lambda }$ is. I assume it is supposed to be a helicity eigenstate, like $\xi _{\lambda }$ , but it is not actually defined as such anywhere. (Bjfar (talk) 03:10, 22 April 2013 (UTC))[reply]

I'm fairly confident that

\chi _{\lambda }=\xi _{\lambda }

and its just a screw-up typo in the equations. But not my ball-o-wax, so I won't mess with it. Yes this needs to be fixed. 67.198.37.16 (talk) 03:16, 1 December 2020 (UTC)[reply]