H1K0Event2.C

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// Class H1K0Event2
//
// Author: Benno List, Jenny Boehme
// Last update: $Date: 2005/01/12 10:11:44 $
//          by: $Author: blist $
// 
// Description: class to generate and fit K0S decays
//               
#include "jbltools/kinfit/H1K0Event2.h"

#include "jbltools/kinfit/JetFitObject.h"
#include "jbltools/kinfit/MassConstraint.h"
#include "jbltools/kinfit/cernlib.h"
#include "jbltools/kinfit/NeutralParticleTrack.h"
#include "jbltools/kinfit/ChargedParticleTrack.h"
#include "jbltools/kinfit/ThreeVector.h"
#include "jbltools/kinfit/FourVector.h"
#include "jbltools/kinfit/TTVertexConstraint.h"
#include "jbltools/kinfit/VertexConstraint.h"
#include "jbltools/kinfit/VertexFitObject.h"
#include "jbltools/kinfit/TrackMomentumConstraint.h"

#include "jbltools/kinfit/H1Tracks.h"

#include <iostream>              // - cout
using std::cout;
using std::endl;
#include <cmath>  
using std::pow;            
using std::atan;            
using std::exp;            
using std::sin;            
using std::cos;            
using std::log;            
using std::abs;            

// constructor: 
H1K0Event2::H1K0Event2(H1Tracks& nt_, int t1, int t2)
: nt (nt_)
 {
  for (int i = 0; i < NFV; ++i) fv[i] = 0;
  for (int i = 0; i < NTFO; ++i) rectrack[i] = 0;
  
  rectrack[1] = new ChargedParticleTrack ("pi1", nt.Par+5*t1, nt.Cov+15*t1, 0.13957);
  rectrack[2] = new ChargedParticleTrack ("pi2", nt.Par+5*t2, nt.Cov+15*t2, 0.13957);
  
  ThreeVector nominalvertex;
  ThreeVector k0recmom = (rectrack[1]->getMomentum (0) + rectrack[2]->getMomentum (0)).getThreeVector();
  rectrack[0] = new NeutralParticleTrack ("K0 rec", nominalvertex, k0recmom, 0.497648);
};

//destructor: 
H1K0Event2::~H1K0Event2() {
  for (int i = 0; i < NFV; ++i) delete fv[i];
  for (int i = 0; i < NTFO; ++i) {
    delete rectrack[i];
  }  
};


// fit it!
int H1K0Event2::fitEvent (BaseFitter& fitter){
  
  fitter.addFitObject (rectrack[0]);
  fitter.addFitObject (rectrack[1]);
  fitter.addFitObject (rectrack[2]);

  k0decvertex = new VertexFitObject ("K0dec", 0, 0, 0);
  fitter.addFitObject (k0decvertex);
  
  rectrack[0]->fixVertexParam (0);
  k0decvertex->addTrack (rectrack[0], true, false);
  k0decvertex->addTrack (rectrack[1], false, true);
  k0decvertex->addTrack (rectrack[2], false, true);
  
  k0decvertex->addConstraints (fitter, VertexFitObject::VXYZ|VertexFitObject::PXYZ);
  
  k0decvertex->initForFit();
  
  double prob = fitter.fit();
  
//   std::cout << "  Fit prob: " << prob << std::endl;
//   std::cout << "  Fitted vertex: " << *k0decvertex << std::endl;
     
   return fitter.getError();
};

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