ToSFAD[exp]
converts all propagator denominators written as FAD
or FeynAmpDenmoninator[...,PropagatorDenominator[...],...]
to SFAD
or FeynAmpDenmoninator[...,StandardPropagatorDenominator[...],...]
respectively.
[FAD[p]] ToSFAD
\frac{1}{(p^2+i \eta )}
[FAD[p]] // StandardForm
ToSFAD
(*FeynAmpDenominator[StandardPropagatorDenominator[Momentum[p, D], 0, 0, {1, 1}]]*)
[FAD[{p, m}]] ToSFAD
\frac{1}{(p^2-m^2+i \eta )}
[FAD[{p, m}]] // StandardForm
ToSFAD
(*FeynAmpDenominator[StandardPropagatorDenominator[Momentum[p, D], 0, -m^2, {1, 1}]]*)
[FAD[{p + q, m, 2}]] ToSFAD
\frac{1}{((p+q)^2-m^2+i \eta )^2}
[FAD[{p + q, m, 2}]] // StandardForm
ToSFAD
(*FeynAmpDenominator[StandardPropagatorDenominator[Momentum[p + q, D], 0, -m^2, {1, 1}], StandardPropagatorDenominator[Momentum[p + q, D], 0, -m^2, {1, 1}]]*)