void udw()
{
   //
   // ud W vertex
   //
   TCanvas *c1 = new TCanvas("udw", "udw", 740,40, 300, 300);
   c1->Range(0, 3, 60, 57);
   Int_t linsav = gStyle->GetLineWidth();
   gStyle->SetLineWidth(3);
   TLatex t;
   t.SetTextAlign(22);
   t.SetTextSize(0.1);
   TLine * l;

   // Incoming u, outgoing d
   l = new TLine(50, 50, 30, 30); l->Draw();
   l = new TLine(10, 50, 30, 30); l->Draw();

   t.DrawLatex(7,53,"u(c,t)");
   t.DrawLatex(48,53,"d'(s',b')");

   // W propagator
   lc = new TCurlyLine(30, 30, 30, 5);
   lc->SetWavy();
   lc->Draw();
   // t.DrawLatex(25, 17.5,"Z^{0}/#gamma");
   t.DrawLatex(25, 17.5,"W^{#pm}");

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