Name: Alexander Sandrock Date: 11/18/13-01:46:34 PM Z


An example I have encountered is the following (e+ e- -> mu+ mu-):

test = SpinorUBar[k2, m2].GA[mu].SpinorV[k1, m2] SpinorU[p1, m1].GA[
    mu].SpinorVBar[p2, m1] FeynAmpDenominator[
   PropagatorDenominator[s]]
ctest = ComplexConjugate[test]
FermionSpinSum[test ctest]