TOPMCTrackMakerModule.cc

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
// Own header.
#include <top/modules/TOPMCTrackMaker/TOPMCTrackMakerModule.h>
 
// framework - DataStore
#include <framework/datastore/StoreArray.h>
 
// framework aux
#include <framework/gearbox/Unit.h>
#include <framework/gearbox/Const.h>
#include <framework/geometry/BFieldManager.h>
 
// dataobjects
#include <mdst/dataobjects/Track.h>
#include <mdst/dataobjects/TrackFitResult.h>
#include <tracking/dataobjects/ExtHit.h>
#include <mdst/dataobjects/MCParticle.h>
#include <top/dataobjects/TOPBarHit.h>
 
using namespace std;
 
namespace Belle2 {
 
  //-----------------------------------------------------------------
  //-----------------------------------------------------------------
 
  REG_MODULE(TOPMCTrackMaker);
 
  //-----------------------------------------------------------------
  //                 Implementation
  //-----------------------------------------------------------------
 
  TOPMCTrackMakerModule::TOPMCTrackMakerModule() : Module()
 
  {
    // set module description (e.g. insert text)
    setDescription("Constructs Tracks and ExtHits from MCParticles and TOPBarHits. "
                   "Utility needed for testing and debugging of TOP reconstruction.");
    setPropertyFlags(c_ParallelProcessingCertified);
 
    // Add parameters
 
  }
 
  void TOPMCTrackMakerModule::initialize()
  {
 
    // input
 
    StoreArray<MCParticle> mcParticles;
    mcParticles.isRequired();
 
    StoreArray<TOPBarHit> barHits;
    barHits.isRequired();
 
    // output
 
    StoreArray<Track> tracks;
    tracks.registerInDataStore();
 
    StoreArray<TrackFitResult> fitResults;
    fitResults.registerInDataStore();
 
    StoreArray<ExtHit> extHits;
    extHits.registerInDataStore();
 
    tracks.registerRelationTo(mcParticles);
    tracks.registerRelationTo(extHits);
 
  }
 
  void TOPMCTrackMakerModule::event()
  {
 
    StoreArray<MCParticle> mcParticles;
    StoreArray<TOPBarHit> barHits;
 
    StoreArray<Track> tracks;
    StoreArray<TrackFitResult> fitResults;
    StoreArray<ExtHit> extHits;
 
    for (const auto& mcParticle : mcParticles) {
      if (mcParticle.getStatus(MCParticle::c_PrimaryParticle) == 0) continue;
      if (mcParticle.getCharge() == 0) continue;
      const auto* barHit = mcParticle.getRelated<TOPBarHit>();
      if (!barHit) continue;
 
      TMatrixDSym cov(6); // infinite precision
      fitResults.appendNew(mcParticle.getVertex(),
                           mcParticle.getMomentum(),
                           cov,
                           mcParticle.getCharge(),
                           Const::pion,
                           1.0,            // pValue
                           BFieldManager::getField(0, 0, 0).Z() / Unit::T,
                           0x38FFFFFFFFFFFFFF, // 56 hits, in all CDC layers
                           0, 56 - 5); // NDF = 56-5
      auto* track = tracks.appendNew();
      track->setTrackFitResultIndex(Const::pion, fitResults.getEntries() - 1);
      track->addRelationTo(&mcParticle);
 
      const Const::ChargedStable& chargedStable = Const::pion;
      double pmom = barHit->getMomentum().R();
      double mass = chargedStable.getMass();
      double beta = pmom / sqrt(pmom * pmom + mass * mass);
      double tof = barHit->getLength() / beta / Const::speedOfLight;
      const auto* extHit = extHits.appendNew(tof,
                                             chargedStable.getPDGCode(),
                                             Const::TOP,
                                             barHit->getModuleID(),
                                             EXT_ENTER,
                                             false,
                                             barHit->getPosition(),
                                             barHit->getMomentum(),
                                             cov);
      track->addRelationTo(extHit);
    }
 
  }

} // end Belle2 namespace