FeynArts 3.11; Last update: 18 May 19;

 * Removed spurious Solve::ifun message in the presence of tadpoles.
 * Added GaugeVector object, to facilitate parameterizing e.g. axial gauges.

Author: t-hahn

FeynArts.m

@@ -1,8 +1,8 @@
 (*
 
 This is FeynArts, Version 3.11
-Copyright by Sepp Kueblbeck, Hagen Eck, and Thomas Hahn 1991-2019
-last modified 2 Sep 19 by Thomas Hahn
+Copyright by Sepp Kueblbeck, Hagen Eck, and Thomas Hahn 1991-2020
+last modified 18 May 20 by Thomas Hahn
 
 Release notes:
 
@@ -758,12 +758,12 @@ on a propagator of type t (External, Internal, Loop)."
 "KIi[n] is the ith kinematic index of the nth field in the kinematic
 vector."
 
-KIs = {KI1, KI2, KI3, KI4, KI5, KI6}
+KIs = {KI1, KI2, KI3, KI4, KI5, KI6, KI7, KI8, KI9, KI10, KI11, KI12}
 
 SI::usage = "SI[n] is the nth summation index in a component of the
 kinematic vector."
 
-SIs = {SI1_, SI2_, SI3_, SI4_, SI5_, SI6_}
+SIs = {SI1_, SI2_, SI3_, SI4_, SI5_, SI6_, SI7_, SI8_, SI9_, SI10_, SI11_, SI12_}
 
 CI::usage = "CI[n] is the classes index of the nth field in the
 kinematic vector."
@@ -1263,6 +1263,10 @@ integration momenta of the amplitude (empty for tree graphs)."
 GaugeXi::usage =
 "GaugeXi[s] is a gauge parameter with index s."
 
+GaugeVector::usage =
+"GaugeVector[V, p, (mu)] is a gauge vector for gauge boson V with
+momentum p and Lorentz Index mu, used e.g. in axial gauge."
+
 FourMomentum::usage =
 "FourMomentum[s, n] is the nth momentum of type s.  Allowed types are
 Incoming, Outgoing, External, and Internal."
@@ -1482,8 +1486,8 @@ derived by flip and can have values True (edit the original shape
 
 P$ChainBuildOrder = {F, U}
 
-P$InsertionObjects = G[_][_][__][__] | _Mass | _GaugeXi |
-  VertexFunction[_][__]
+P$InsertionObjects = G[_][_][__][__] | _Mass |
+  _GaugeXi | _GaugeVector | VertexFunction[_][__]
 
 P$Options = (_Rule | _RuleDelayed)...
 
@@ -1492,7 +1496,7 @@ derived by flip and can have values True (edit the original shape
 
 $FeynArtsVersionNumber = 3.11
 
-$FeynArtsVersion = "FeynArts 3.11 (2 Sep 2019)"
+$FeynArtsVersion = "FeynArts 3.11 (18 May 2020)"
 
 $FeynArtsDir = DirectoryName[
   $InputFileName /. HoldPattern[$InputFileName] :>

FeynArts/Analytic.m

@@ -2,7 +2,7 @@
 	Analytic.m
 		Translation of InsertFields output into
 		analytic expressions
-		last modified 24 Sep 19 th
+		last modified 18 May 20 th
 *)
 
 Begin["`Analytic`"]
@@ -197,7 +197,7 @@ Since momenta on tree propagators (Propagator[Internal])
 
 MomConservation[top_, vert_] :=
 Block[ {eq},
-  eq = Plus@@ IncomingMomentum[vert]@@@ top;
+  eq = Plus@@ IncomingMomentum[vert]@@@ top /. _zero -> 0;
   If[ eq === 0 || (Head[eq] === Plus && FreeQ[eq, ZZZ]), top,
     top /. If[ Head[eq] =!= Plus, eq -> zero[eq],
       First[Solve[ eq == 0,