FeynArts 3.7

Author: t-hahn

FeynArts.m

@@ -1,8 +1,8 @@
 (*
 
-This is FeynArts, Version 3.6
-Copyright by Sepp Kueblbeck, Hagen Eck, and Thomas Hahn 1991-2011
-last modified 28 Mar 11 by Thomas Hahn
+This is FeynArts, Version 3.7
+Copyright by Sepp Kueblbeck, Hagen Eck, and Thomas Hahn 1991-2012
+last modified 4 Dec 12 by Thomas Hahn
 
 Release notes:
 
@@ -44,9 +44,9 @@
 
 
 Print[""];
-Print["FeynArts 3.6"];
+Print["FeynArts 3.7"];
 Print["by Hagen Eck, Sepp Kueblbeck, and Thomas Hahn"];
-Print["last revised 28 Mar 11"]
+Print["last revised 4 Dec 12"]
 
 
 BeginPackage["FeynArts`"]
@@ -702,6 +702,11 @@ on a propagator of type t (External, Internal, Loop)."
 
 KIs = {KI1, KI2, KI3, KI4}
 
+SI::usage = "SI[n] is the nth summation index in a component of the
+kinematic vector."
+
+SIs = {SI1_, SI2_, SI3_, SI4}
+
 CI::usage = "CI[n] is the classes index of the nth field in the
 kinematic vector."
 
@@ -986,6 +991,16 @@ as arguments the quantum numbers of the involved fields (times -1 for
 integral.  If no definition is made for ConjugateCoupling, the final
 amplitudes will contain this symbol."
 
+GetCouplings::usage =
+"GetCouplings[C[fi], ...] returns all couplings of the form C[fi] == _
+in M$CouplingMatrices."
+
+ReplaceCouplings::usage =
+"ReplaceCouplings[C[fi] == coup] replaces all couplings matching C[fi]
+in M$CouplingMatrices.  All couplings in M$CouplingMatrices, including
+the former versions of the ones being replaced, may be used on the
+r.h.s. in the form C[fields]."
+
 G::usage =
 "G[sym][cto][fields][kinpart] is a generic coupling matrix of
 counter-term order cto for fields corresponding to the kinematical
@@ -1027,6 +1042,13 @@ as arguments the quantum numbers of the involved fields (times -1 for
 whether momentum conservation at each vertex is enforced.  If set to
 False, every propagator will carry its own momentum."
 
+GraphInfoFunction::usage =
+"GraphInfoFunction is an option of CreateFeynAmp.  It specifies a
+function with which every diagram is multiplied.  The function receives
+two arguments, f[rul, top], where rul are the insertion rules and top
+the corresponding topology of the diagram.  This function can be used
+to add graph information to the amplitude."
+
 VertexDebug::usage =
 "VertexDebug[debuginfo] is a function invoked whenever a vertex cannot
 be resolved.  It is used for debugging FeynArts."
@@ -1113,15 +1135,25 @@ as arguments the quantum numbers of the involved fields (times -1 for
 
 $FermionLines::usage =
 "$FermionLines is a FeynArts system constant that can be True or False
-indicating whether CreateFeynAmp should collect fermion fields F in
-lines or not.  Fermion line construction has to be turned off for
-generic models that contain couplings involving more than two fermions
-(it is for example impossible to reliably determine how two fermion
-lines run through a 4-fermion vertex).  In such a case the fermions
-should carry a kinematical (e.g. Dirac) index.  Note that if
-$FermionLines = False the classes option MatrixTraceFactor has no effect
-on fermionic classes and also no additional minus signs are inserted for
-odd permutations of external fermions."
+indicating whether CreateFeynAmp should collect Grassmann-valued fields
+(typically F and U) in lines or not.
+Fermion line construction has to be turned off for generic models that
+contain couplings involving more than two fermions (it is for example
+impossible to reliably determine how two fermion lines run through a
+four-fermion vertex).  In such a case the fermions should carry a
+kinematical (e.g. Dirac) index.
+Note that if $FermionLines = False, the M$ClassesDescription option
+MatrixTraceFactor has no effect on fermionic classes and also no
+additional minus signs are inserted for odd permutations of external
+fermions."
+
+$SparseCouplings::usage =
+"$SparseCouplings is a FeynArts system constant.  If set to True, a
+model is initialized such that all zero-components of the coupling
+vector are handled by a single default rule, which speeds up lookup of
+Feynman rules in the presence of large but sparse coupling vectors.
+Use with care, as individual checks of the kinematical components are
+not possible anymore then."
 
 FeynAmp::usage =
 "FeynAmp is the head of a data structure that represents the analytical
@@ -1326,7 +1358,7 @@ topologies where it specifies whether the field numbers (the n in
 P$Options = (_Rule | _RuleDelayed)...
 
 
-$FeynArts = 3.6
+$FeynArts = 3.7
 
 $FeynArtsDir = DirectoryName[ File /.
   FileInformation[System`Private`FindFile[$Input]] ]

FeynArts/Analytic.m

@@ -2,7 +2,7 @@
 	Analytic.m
 		Translation of InsertFields output into
 		analytic expressions
-		last modified 28 Mar 11 th
+		last modified 8 Oct 12 th
 *)
 
 Begin["`Analytic`"]
@@ -12,7 +12,8 @@
   GaugeRules -> {_GaugeXi -> 1},
   PreFactor -> -I (2 Pi)^(-4 LoopNumber),
   Truncated -> False,
-  MomentumConservation -> True
+  MomentumConservation -> True,
+  GraphInfoFunction -> (1 &)
 }
 
 (* for D dimensions use
@@ -54,8 +55,8 @@
   CreateFeynAmp[ TopologyList[][tops], opt ]
 
 CreateFeynAmp[ tops:TopologyList[info___][___], options___Rule ] :=
-Block[ {alevel, pref, next, gaugeru, truncru, momcons, amps, head,
-topnr = 1, opt = ActualOptions[CreateFeynAmp, options]},
+Block[ {alevel, pref, next, gaugeru, truncru, momcons, graphinfo, toplist,
+amps, head, topnr = 1, opt = ActualOptions[CreateFeynAmp, options]},
 
   If[ (alevel = ResolveLevel[AmplitudeLevel /. opt /. {info} /.
         Options[InsertFields]]) === $Failed,
@@ -73,6 +74,8 @@
   gaugeru = GaugeRules /. opt;
   truncru = If[ TrueQ[Truncated /. opt], M$TruncationRules, {} ];
   momcons = TrueQ[MomentumConservation /. opt];
+  graphinfo = GraphInfoFunction /. opt;
+  toplist = TopologyList[info];
 
   amps = PickLevel[alevel][tops];
   Scan[ If[FreeQ[amps, #], Message[CreateFeynAmp::nolevel, #]]&, alevel ];
@@ -85,7 +88,8 @@
 
   head = FeynAmpList[info] /.
     (Process -> iorule_) :> (Process ->
-      MapIndexed[{#1, iomom@@ #2, TheMass[#1, External]}&, iorule, {2}]) /.
+      MapIndexed[{#1, iomom@@ #2, TheMass[#1, External],
+        QuantumNumbers[ToClasses[#1]]}&, iorule, {2}]) /.
     (InsertionLevel -> _) :> (AmplitudeLevel -> alevel);
 
   amps = head@@ amps /. _MTF -> 1 /. gaugeru //. M$LastModelRules;
@@ -124,7 +128,7 @@
   ];
 	(* renumber the internal momenta *)
   oldmom = Union[ Cases[momtop, FourMomentum[_ZZZ, _], Infinity] ];
-  imom = Apply[RenumberMom, oldmom, 1];
+  imom = RenumberMom@@@ oldmom;
   momtop = momtop /. Thread[oldmom -> imom];
 
   toppref = pref /. LoopNumber :> Genus[top];
@@ -226,7 +230,7 @@ Since momenta on tree propagators (Propagator[Internal])
   rawgm = gm /.
     s1_. _[__, orig[s2_, fi_], k___] :>
       app[ If[s1 === s2, fi, anti[fi]], k ];
-  Append[amp, gm -> (CreateAmpIns[rawgm, s mtf, #]&)/@ ins] /.
+  Append[amp, gm -> (CreateAmpIns[top, rawgm, s mtf, #]&)/@ ins] /.
     orig[__] :> Seq[]
 ]
 
@@ -514,10 +518,11 @@ need another (-1)^(Length[ext]/2).
   SumOver[i, l, ext] /; r === Range[l]
 
 
-CreateAmpIns[ gm_, sgen_, gr_ -> ins_ ] :=
-  CreateAmpIns[gm, sgen, gr] -> (CreateAmpIns[gm, sgen, #]&)/@ ins
+CreateAmpIns[ top_, gm_, sgen_, gr_ -> ins_ ] :=
+  CreateAmpIns[top, gm, sgen, gr] ->
+    (CreateAmpIns[top, gm, sgen, #]&)/@ ins
 
-CreateAmpIns[ gm_, sgen_, gr:FeynmanGraph[s_, ___][ru__] ] :=
+CreateAmpIns[ top_, gm_, sgen_, gr:FeynmanGraph[s_, ___][ru__] ] :=
 Block[ {ext, int, ins, deltas},
   ins = ReplacePart[gm, sgen/s, -1] /. {ru} /.
     anti -> AntiParticle /.
@@ -530,6 +535,7 @@ need another (-1)^(Length[ext]/2).
   ext = Union[Cases[Take[{ru}, next], _Index, Infinity]];
   int = Complement[Cases[Drop[{ru}, next], _Index, Infinity], ext];
   ins[[-1]] *=
+    graphinfo[FeynmanGraph[ru], top, toplist] *
     Times@@ deltas *
     Times@@ (SumOver[#, IndexRange[Take[#, 1]], External]&)/@ ext *
     Times@@ (SumOver[#, IndexRange[Take[#, 1]]]&)/@ int;
@@ -554,7 +560,7 @@ kinematical expression (for a G[-]).  If neither method resolves TheC,
   ferm = Cases[vert, _. _F];
   vert = vert[[perm]];
   kin = k /. MapIndexed[KinRule, perm];
-  If[ ferm =!= Cases[vert, _. _F],
+  If[ Length[M$FlippingRules] > 0 && ferm =!= Cases[vert, _. _F],
     If[ Length[ferm] > 2, Message[CreateFeynAmp::ambig, vert] ];
     kin = kin /. M$FlippingRules ];