void ggg()
{
   //
   // qqg vertex
   //
   TCanvas *c1 = new TCanvas("ggg", "ggg", 740,40, 300, 300);
   c1->Range(3, 3, 57, 57);
   Int_t linsav = gStyle->GetLineWidth();
   gStyle->SetLineWidth(3);
   TLatex t;
   t.SetTextAlign(22);
   t.SetTextSize(0.1);
   TLine * l;

   // Incoming gg
   lc = new TCurlyLine(50, 50, 30, 30);  lc->SetCurly(); lc->Draw();
   lc = new TCurlyLine(10, 50, 30, 30);  lc->SetCurly(); lc->Draw();

   t.DrawLatex(7,53,"g");
   t.DrawLatex(53,53,"g");

   // gluon propagator
   lc = new TCurlyLine(30, 30, 30, 5);
   lc->SetCurly();
   lc->Draw();
   t.DrawLatex(25, 17.5,"g");

   c1->Update();
   gStyle->SetLineWidth(linsav);
}