Name: Fabrizio Date: 06/21/11-10:56:11 PM Z


Excuse me.

\[CapitalDelta]g[k_, p_, \[Mu]_, \[Nu]_, m_, \[Xi]_] := -I Contract[
   (MTD[\[Mu], \[Nu]] - (1 - \[Xi]) (FVD[k, \[Mu]] -
          FVD[p, \[Mu]]).(FVD[k, \[Nu]] - FVD[p, \[Nu]]).FAD[{k - p,
          Sqrt[\[Xi]] m}]).FAD[{k - p, m}]]

which seems to reproduce the propagator (OK?)

Also, PL = (1 - GAD[5])/2;