DTrackTimeBased_factory_Combo.cc

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// $Id$
//
//    File: DTrackTimeBased_factory_Combo.cc
// Created: Tue Aug  9 14:29:24 EST 2011
// Creator: pmatt
//

#ifdef VTRACE
#include "vt_user.h"
#endif

#include "DTrackTimeBased_factory_Combo.h"

//------------------
// init
//------------------
jerror_t DTrackTimeBased_factory_Combo::init(void)
{
   //BEWARE: IF THIS IS CHANGED, CHANGE IN THE ANALYSIS UTILITIES AND THE EVENT WRITER ALSO!!
   dTrackSelectionTag = "PreSelect";
   gPARMS->SetDefaultParameter("COMBO:TRACK_SELECT_TAG", dTrackSelectionTag);

   //remember, charge sign could have flipped during track reconstruction
   //order of preference:
      //very similar mass & charge (e.g. pi -> mu, e)
      //slightly similar mass & charge (e.g. pi -> K)
      //similar mass, different charge (e.g. pi+ -> pi-)
      //don't need to list every PID: if none of the below PIDs are available, will choose the one with the best PID FOM

   dParticleIDsToTry.emplace(PiPlus, vector<Particle_t>{KPlus, PiMinus, KMinus, Proton});
   dParticleIDsToTry.emplace(PiMinus, vector<Particle_t>{KMinus, PiPlus, KPlus});
   dParticleIDsToTry.emplace(KPlus, vector<Particle_t>{PiPlus, KMinus, PiMinus, Proton});
   dParticleIDsToTry.emplace(KMinus, vector<Particle_t>{PiMinus, KPlus, PiPlus, Proton});

   dParticleIDsToTry.emplace(Proton, vector<Particle_t>{KPlus, PiPlus, KMinus});
   dParticleIDsToTry.emplace(AntiProton, vector<Particle_t>{KMinus, Proton, PiMinus, KPlus});

   dParticleIDsToTry.emplace(Positron, vector<Particle_t>{PiPlus, KPlus, PiMinus, KMinus});
   dParticleIDsToTry.emplace(Electron, vector<Particle_t>{PiMinus, KMinus, PiPlus, KPlus});

   dParticleIDsToTry.emplace(MuonPlus, dParticleIDsToTry[Positron]);
   dParticleIDsToTry.emplace(MuonMinus, dParticleIDsToTry[Electron]);

   dParticleIDsToTry.emplace(Deuteron, vector<Particle_t>{Proton, KPlus, PiPlus});

   return NOERROR;
}

//------------------
// brun
//------------------
jerror_t DTrackTimeBased_factory_Combo::brun(jana::JEventLoop *locEventLoop, int32_t runnumber)
{
   //Get Needed PIDs
   auto locReactions = DAnalysis::Get_Reactions(locEventLoop);
   for(size_t loc_i = 0; loc_i < locReactions.size(); ++loc_i)
   {
      auto locPositivePIDs = locReactions[loc_i]->Get_FinalPIDs(-1, false, false, d_Positive, false);
      for(auto& locPID : locPositivePIDs)
         dPositivelyChargedPIDs.insert(locPID);

      auto locNegativePIDs = locReactions[loc_i]->Get_FinalPIDs(-1, false, false, d_Negative, false);
      for(auto& locPID : locNegativePIDs)
         dNegativelyChargedPIDs.insert(locPID);
   }

   return NOERROR;
}

//------------------
// evnt
//------------------
jerror_t DTrackTimeBased_factory_Combo::evnt(jana::JEventLoop *locEventLoop, uint64_t eventnumber)
{
#ifdef VTRACE
   VT_TRACER("DTrackTimeBased_factory_Combo::evnt()");
#endif

   vector<const DChargedTrack*> locChargedTracks;
   locEventLoop->Get(locChargedTracks, dTrackSelectionTag.c_str());

   for(auto& locTrack : locChargedTracks)
   {
      if(locTrack->Contains_Charge(1))
         Create_PIDsAsNeeded(locTrack, dPositivelyChargedPIDs);
      if(locTrack->Contains_Charge(-1))
         Create_PIDsAsNeeded(locTrack, dNegativelyChargedPIDs);
   }

   return NOERROR;
}

void DTrackTimeBased_factory_Combo::Create_PIDsAsNeeded(const DChargedTrack* locChargedTrack, set<Particle_t>& locPIDs)
{
   for(auto& locPID : locPIDs)
   {
      if(locChargedTrack->Get_Hypothesis(locPID) != nullptr)
         continue; //already exists

      const DChargedTrackHypothesis* locChargedTrackHypothesis = Get_ChargedHypothesisToUse(locChargedTrack, locPID);

      DTrackTimeBased* locTrackTimeBased = Convert_ChargedTrack(locChargedTrackHypothesis, locPID);
      locTrackTimeBased->AddAssociatedObject(locChargedTrack);
      _data.push_back(locTrackTimeBased);
   }
}

const DChargedTrackHypothesis* DTrackTimeBased_factory_Combo::Get_ChargedHypothesisToUse(const DChargedTrack* locChargedTrack, Particle_t locDesiredPID)
{
   //pid not found for this track: loop over other possible pids
   for(auto& locPID : dParticleIDsToTry[locDesiredPID])
   {
      const DChargedTrackHypothesis* locChargedTrackHypothesis = locChargedTrack->Get_Hypothesis(locPID);
      if(locChargedTrackHypothesis != nullptr)
         return locChargedTrackHypothesis;
   }

   //still none found, take the one with the best FOM
   return locChargedTrack->Get_BestFOM();
}

DTrackTimeBased* DTrackTimeBased_factory_Combo::Convert_ChargedTrack(const DChargedTrackHypothesis* locChargedTrackHypothesis, Particle_t locNewPID)
{
   auto locOriginalTrackTimeBased = locChargedTrackHypothesis->Get_TrackTimeBased();
   auto locTrackTimeBased = new DTrackTimeBased(*locOriginalTrackTimeBased);
   locTrackTimeBased->setPID(locNewPID);
   
   locTrackTimeBased->AddAssociatedObject(locOriginalTrackTimeBased);
   return locTrackTimeBased;
}