Hi. I was reading Griffiths page 289 and I wasn't sure how the transition from Eq. (8.45) to (8.46) was allowed. What bothers me is factoring out the "color factors" since the c's are vectors, and generally the elements of these color factors are matrices. For example, how is it allowed to pull out [itex]c_3^\dagger \lambda^\alpha c_1[/itex] out of [itex] \bar{u}(3)c_3^\dagger \lambda^\alpha \gamma^\mu u(1) c_1 [/itex]. Is it because the color factors live in a different space (color space) so they commute with spinor-space matrices?(adsbygoogle = window.adsbygoogle || []).push({});

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# Color factor

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