FeynCalc manual (development version)

CartesianPropagatorDenominator

CartesianPropagatorDenominator[propSq + ..., propEik + ..., m^2, {n, s}] encodes a generic Cartesian propagator denominator of the form \frac{1}{[(q1+...)^2 + q1.p1 + ... + m^2 + s*I \eta]^n}

propSq should be of the form CartesianMomentum[q1, D - 1], while propEik should look like CartesianPair[CartesianMomentum[q1, D - 1], CartesianMomentum[p1, D - 1].

CartesianPropagatorDenominator is an internal object. To enter such propagators in FeynCalc you should use CFAD.

See also

Overview, CFAD, FeynAmpDenominator.

Examples

Standard 3-dimensional Cartesian propagator

FeynAmpDenominator[CartesianPropagatorDenominator[CartesianMomentum[p, D - 1], 0, m^2, {1, -1}]]

\frac{1}{(p^2+m^2-i \eta )}

Here we switch the sign of the mass term

FeynAmpDenominator[CartesianPropagatorDenominator[CartesianMomentum[p, D - 1], 0, -m^2, {1, -1}]]

\frac{1}{(p^2-m^2-i \eta )}

And here also the sign of i \eta

FeynAmpDenominator[CartesianPropagatorDenominator[CartesianMomentum[p, D - 1], 0, -m^2, {1, +1}]]

\frac{1}{(p^2-m^2+i \eta )}

Eikonal Cartesian propagator with a residual mass term

FeynAmpDenominator[CartesianPropagatorDenominator[0, 
   CartesianPair[CartesianMomentum[p, D - 1], CartesianMomentum[q, D - 1]], m^2, {1, -1}]]

\frac{1}{(p\cdot q+m^2-i \eta )}