Does anyone know exactly how Srednicki identitifies the electromagnetic gauge field with his [itex]l,r,b [/itex] fields. I know he is trying to match covariant derivatives, i.e.(adsbygoogle = window.adsbygoogle || []).push({});

[itex] D_{\mu} p=(\partial_{\mu}-il_{\mu})p[/itex] with [itex]D_{\mu} p=(\partial_{\mu}-ieA_{\mu})p[/itex]

and that he has set [itex]l_{\mu}=l_{\mu}^a T^a+b_{\mu} [/itex]

and also match [itex] D_{\mu} n=(\partial_{\mu}-ir_{\mu})n[/itex] with [itex]D_{\mu} n=(\partial_{\mu})n[/itex]

and that he has set [itex]r_{\mu}=r_{\mu}^a T^a+b_{\mu} [/itex]

But I don't seem to be able to work out the fine print of arriving at (90.20):

[tex] eA_{\mu}=l^3_{\mu}+r_{\mu}^3+1/2b_{\mu} [/tex]

from these.

I guess it must be quite simple, and I thought maybe I should just expand the [itex]T^{a} [/itex] gens in terms of Pauli then solve simultaneously, but this didn't quite seem to work out..

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# Srednicki (ch90)

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