Converting TEvtGen to native cmake

[u/mrichter/AliRoot.git] / TEvtGen / EvtGen / EvtGenModels / EvtVVPIPI_WEIGHTED.cpp

diff --git a/TEvtGen/EvtGen/EvtGenModels/EvtVVPIPI_WEIGHTED.cpp b/TEvtGen/EvtGen/EvtGenModels/EvtVVPIPI_WEIGHTED.cpp
new file mode 100644 (file)
index 0000000..b827938
--- /dev/null
+++ b/TEvtGen/EvtGen/EvtGenModels/EvtVVPIPI_WEIGHTED.cpp
@@ -0,0 +1,135 @@
+//--------------------------------------------------------------------------
+//
+// 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: EvtVVSPwave.cc
+//
+// Description: Routine to decay vector-> vector pi pi where the 
+//              decay is S-wave dominated.
+//
+// Modification history:
+//
+// Jim Hunt      June 4, 2008 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/EvtTensor4C.hh"
+#include "EvtGenBase/EvtReport.hh"
+#include "EvtGenModels/EvtVVPIPI_WEIGHTED.hh"
+#include <string>
+using std::endl;
+
+EvtVVPIPI_WEIGHTED::~EvtVVPIPI_WEIGHTED() {}
+
+std::string EvtVVPIPI_WEIGHTED::getName(){
+
+  return "VVPIPI_WEIGHTED";     
+
+}
+
+
+EvtDecayBase* EvtVVPIPI_WEIGHTED::clone(){
+
+  return new EvtVVPIPI_WEIGHTED;
+
+}
+
+void EvtVVPIPI_WEIGHTED::init(){
+
+  static EvtId PIP=EvtPDL::getId("pi+");
+  static EvtId PIM=EvtPDL::getId("pi-");
+  static EvtId PI0=EvtPDL::getId("pi0");
+
+  // check that there are 0 arguments
+  checkNArg(0);
+  checkNDaug(3);
+
+  checkSpinParent(EvtSpinType::VECTOR);
+  checkSpinDaughter(0,EvtSpinType::VECTOR);
+
+
+
+  if ((!(getDaug(1)==PIP&&getDaug(2)==PIM))&&
+      (!(getDaug(1)==PI0&&getDaug(2)==PI0))) {
+    report(ERROR,"EvtGen") << "EvtVVPIPI_WEIGHTED generator expected "
+                           << " pi+ and pi- (or pi0 and pi0) "
+                           << "as 2nd and 3rd daughter. "<<endl;
+    report(ERROR,"EvtGen") << "Will terminate execution!"<<endl;
+    ::abort();
+  }
+
+}
+
+void EvtVVPIPI_WEIGHTED::initProbMax() {
+  //Hard coded... should not be hard to calculate...
+  setProbMax(0.08* 1.13 );
+}      
+
+double reweight_event(double pipi_mass)
+{
+    pipi_mass *= 1000.0;
+    return sqrt(
+        -3.6911336508223251 +
+        0.019119831948029617 * pipi_mass +
+        -1.8962883732377376e-05 * pipi_mass * pipi_mass
+        );
+}
+
+void EvtVVPIPI_WEIGHTED::decay( EvtParticle *psi_prime){
+
+  psi_prime->initializePhaseSpace(getNDaug(),getDaugs());
+
+  EvtParticle *jpsi,*pi1,*pi2;
+  
+  jpsi=psi_prime->getDaug(0);
+  pi1=psi_prime->getDaug(1);
+  pi2=psi_prime->getDaug(2);
+
+//  Put phase space results into the daughters.
+  
+  EvtVector4C ep0,ep1,ep2;  
+  
+  ep0=psi_prime->eps(0);
+  ep1=psi_prime->eps(1);
+  ep2=psi_prime->eps(2);
+
+  EvtVector4C e0,e1,e2;  
+
+  e0 = jpsi->epsParent(0);
+  e1 = jpsi->epsParent(1);
+  e2 = jpsi->epsParent(2);
+
+  double mass2 = (pi1->getP4()+pi2->getP4()).mass2();
+
+  double fac = mass2-4*pi1->mass()*pi2->mass();
+
+  fac *= reweight_event(sqrt(mass2));
+
+  vertex(0,0,fac*(ep0*e0.conj()));
+  vertex(0,1,fac*(ep0*e1.conj()));
+  vertex(0,2,fac*(ep0*e2.conj()));
+  
+  vertex(1,0,fac*(ep1*e0.conj()));
+  vertex(1,1,fac*(ep1*e1.conj()));
+  vertex(1,2,fac*(ep1*e2.conj()));
+  
+  vertex(2,0,fac*(ep2*e0.conj()));
+  vertex(2,1,fac*(ep2*e1.conj()));
+  vertex(2,2,fac*(ep2*e2.conj()));
+
+  return ;
+
+}
+