I have a problem with that equation. I understand (dont know if I'm right) that ##p = - M##. But than, isn't ##g\left( { - {{{p^2}} \over {{M^2}}}} \right)## just equal ##g\left( { - 1} \right)##?(adsbygoogle = window.adsbygoogle || []).push({});

And my bigest problem: in 12.66

##\left[ {p{\partial \over {\partial p}} - \beta \left( \lambda \right){\partial \over {\partial \lambda }} + 2 - 2\gamma \left( \lambda \right)} \right]{G^{\left( 2 \right)}}\left( p \right) = 0##

Where dose the free 2 (after the ##\beta ## term) comes from?

From looking at 12.78 and 12.84 I realize it's the inverse mass dimantionalty of ##G##, But how did it got ther?

Any help would be apriciated :)

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# Peskin Equation 12.66

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