Take a look at the attachment, my question is obvious from the colored points. The attachment is from:(adsbygoogle = window.adsbygoogle || []).push({});

"state-of-the-art formulas for helicity amplitude calculation and all that

(version 2.4)

PART Ia. Spherical-Vector Method for Helicity Amplitudes

(FORMALISM)

Ken-ichi Hikasa"

I think there is a problem with the [itex](-1)[/itex] term. If

[itex]u^{1}_{h}(p)= (-1)^{h-\frac{1}{2}} e^{2ih \bar{\phi}} u^{2}_{h}(p)[/itex]

Then I think when he did the substitution to my underlined step there should be a:

[itex](-1)^{\frac{1}{2}-h} [/itex] instead... At first I thought I had derived wrong the particle 1-2 spinors relation, but my idea is also boosted from the fact he changes the sign of the exponential.

The same is also true for the antiparticle spinor [itex]v[/itex] (blue)

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# Problem with derivation of phase for 1-fermion state

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