Diagram Generation: NOEXTSELF_ is not working?

[mnklann]

When generating diagrams directly in FORM, I found that the option NoExtSelf_ does not appear to have any effect. Even with this option set, FORM still produces diagrams with self-energy insertions on external legs.

For comparison, when using QGRAF with the "onshell" option, these self-energies are absent. I would have expected NoExtSelf_ in FORM to produce the same behavior, but I cannot reproduce the QGRAF results.

Model F34;
  Particle f, +1;
  Vertex f, f, f: g^1;
  Vertex f, f, f, f: g^2;
EndModel;

#define EDGES "10"
#define LOOPS "1"

Auto V p, q;
Set qq: q1, ..., q`EDGES';
Set pp: p1, ..., p`EDGES';
CF U(s), acc;
Auto S x;

L F = diagrams_(F34,{f,f,f,f},{},qq,pp,`LOOPS',`NOEXTSELF_');
.sort(PolyFun=acc)
* some formatting
id acc(x?) = 1;
id topo_(x?) = 1;
id node_(x1?,x2?,x3?) = 1;
id node_(x1?,x2?,?x) = node_(?x);
Repeat id node_(?x1,f(+p?pp[x]),?x2) = node_(?x1,+x,?x2);
Repeat id node_(?x1,f(-p?pp[x]),?x2) = node_(?x1,+x,?x2);
Repeat id node_(?x1,f(+p?qq[x]),?x2) = node_(?x1,-x,?x2);
Repeat id node_(?x1,f(-p?qq[x]),?x2) = node_(?x1,-x,?x2);
Multiply replace_(node_,U);
* 55 Terms after generating the graphs directly
.sort
* 39 Terms after removing external self-energy
id U(x?neg_,x1?,x2?)*U(x3?pos_,x1?,x2?) = 0;
.end

[tueda]

Thank you for testing.

You are right. diagrams_ ignores NOEXTSELF_ in the current master branch. topologies_ should accept NOEXTSELF_, I believe, but crashes for some reason.