SpinFactor.cpp

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// author: Jonas Rademacker (Jonas.Rademacker@bristol.ac.uk)
// status:  Mon 9 Feb 2009 19:18:12 GMT
#include "Mint/SpinFactor.h"
#include "Mint/Utils.h"
#include <algorithm> // for swap
#include <cstdlib>

using namespace std;
using namespace MINT;

TLorentzVector SpinFactor::p(int i, IDalitzEvent& evt){
  // momenta of the fsPS.
  if(i >= (int) fsPS.size() || i < 0){
    throw "index out of range";
  }else{
    if(! fsPS[i] ){
      throw "tree not parsed";
    }
    
    /*
      debug code, leave it in for now:
      std::cout << " SpinFactor p(" << i << ") called" << endl;
      cout << " fsPs[i] " << fsPS[i] << endl;
      cout << "fsPS[i]->getVal() " << fsPS[i]->getVal() << endl;
      cout << "fsPS[i]->getVal().asi(0) " << fsPS[i]->getVal().asi(0) << endl;
      
      std::cout << " getEvent() gettin p ("
      << fsPS[i]->getVal().asi(0)
      << ")" << std::endl;
    */
    //theDecay(evt);
    TLorentzVector p4(evt.p(fsPS[i]->getVal().asi(0)));
    if (theDecay(evt).getVal().parityFactor() < 0){
      // if the mother is an anti-particle, we multiply all
      // 3 momenta with -1. This makes an "anti" tree a CP
      // conjugate tree, not just C conjuate.
      // See also the comment in DecayTreeItem.h.
      p4.SetX( -p4.X());
      p4.SetY( -p4.Y());
      p4.SetZ( -p4.Z());
    }
    return p4;
  }
}

double SpinFactor::mRes(const MINT::const_counted_ptr<AssociatedDecayTree>& adt, IDalitzEvent& evt){
  // return PDG mass for final state paticles
  if(adt->isFinalState()) return mRes(adt->getVal(), evt);
  // return sqrt(p^2) for spin projectors  
  return adt->getVal().mReco(&evt) ;  
}

double SpinFactor::mRes(const AssociatedDecayTreeItem& adt, IDalitzEvent& evt){  
  return adt.mRes(&evt);
}

void SpinFactor::printParsing(std::ostream& os) const{
  for(int i=0; i < _nFinal; i++){
    if(0 == fsPS[i]) continue;
    if(i > 0) os << ", ";
    os << " fsPs[" << anythingToString(i) << "] ="
       << fsPS[i]->getVal().name();
  }
  os << endl;
}