content_image/313578.jpg content_image/313580.jpg
The first relation is proved as follows: 

<img src='content_image/313578.jpg'>

The second line comes from using { γ $^{µ}$, γ$^{ν}$} = 2 g $^{µν}$; the third line results from the Dirac equation, ¯ u ( p )( / p + m ) = 0. The proof of the conjugate relation follows the exact same line of reasoning. 

## E.2.2 Diagrammatic Calculation, Massless Photon and Quark Monojet 

<img src='content_image/313580.jpg'>

