AliDecayer realisation for the EvtGen code and EvtGen itself.

[u/mrichter/AliRoot.git] / TEvtGen / EvtGenModels / EvtVSS.cxx

diff --git a/TEvtGen/EvtGenModels/EvtVSS.cxx b/TEvtGen/EvtGenModels/EvtVSS.cxx
new file mode 100644 (file)
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--- /dev/null
+++ b/TEvtGen/EvtGenModels/EvtVSS.cxx
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+//--------------------------------------------------------------------------
+//
+// Environment:
+//      This software is part of the EvtGen package developed jointly
+//      for the BaBar and CLEO collaborations.  If you use all or part
+//      of it, please give an appropriate acknowledgement.
+//
+// Copyright Information: See EvtGen/COPYRIGHT
+//      Copyright (C) 1998      Caltech, UCSB
+//
+// Module: EvtVSS.cc
+//
+// Description: Routine to decay vector-> scalar scalar
+//
+// Modification history:
+//
+//    RYD       November 24, 1996       Module created
+//
+//------------------------------------------------------------------------
+// 
+#include "EvtGenBase/EvtPatches.hh"
+#include <stdlib.h>
+#include "EvtGenBase/EvtParticle.hh"
+#include "EvtGenBase/EvtGenKine.hh"
+#include "EvtGenBase/EvtPDL.hh"
+#include "EvtGenBase/EvtVector4C.hh"
+#include "EvtGenBase/EvtVector4R.hh"
+#include "EvtGenBase/EvtReport.hh"
+#include "EvtGenModels/EvtVSS.hh"
+#include <string>
+
+EvtVSS::~EvtVSS() {}
+
+std::string EvtVSS::getName(){
+
+  return "VSS"; 
+    
+}
+
+
+EvtDecayBase* EvtVSS::clone(){
+
+  return new EvtVSS;
+
+}
+
+void EvtVSS::init(){
+
+  // check that there are 0 arguments
+  checkNArg(0);
+
+  // check that there are 2 daughters
+  checkNDaug(2);
+
+  // check the parent and daughter spins
+  checkSpinParent(EvtSpinType::VECTOR);
+  checkSpinDaughter(0,EvtSpinType::SCALAR);
+  checkSpinDaughter(1,EvtSpinType::SCALAR);
+}
+
+void EvtVSS::initProbMax() {
+
+   setProbMax(1.0);
+
+}      
+
+void EvtVSS::decay( EvtParticle *p){
+
+  p->initializePhaseSpace(getNDaug(),getDaugs());
+
+  EvtVector4R pDaug = p->getDaug(0)->getP4();
+  
+  double norm=1.0/pDaug.d3mag();
+
+  for (int i=0; i<3; i++) vertex(i,norm*pDaug*(p->eps(i)));
+
+  return;
+}
+