KlId.h

/**************************************************************************
 * 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.                  *
 **************************************************************************/
 
#pragma once
 
#include <framework/datastore/StoreArray.h>
#include <mdst/dataobjects/MCParticle.h>
#include <mdst/dataobjects/KLMCluster.h>
#include <mdst/dataobjects/ECLCluster.h>
#include <mdst/dataobjects/TrackFitResult.h>
 
#include <framework/gearbox/Const.h>
#include <framework/geometry/VectorUtil.h>
#include <framework/logging/Logger.h>
#include <tracking/dataobjects/RecoTrack.h>
#include <genfit/Exception.h>
#include <utility>
#include <math.h>
#include <Math/VectorUtil.h>
 
namespace Belle2::KlongId {
 
  int BelleTrackFlag(const Belle2::KLMCluster& cluster, const float angle = 0.26)
  {
    const ROOT::Math::XYZVector& pos = cluster.getClusterPosition();
 
    Belle2::StoreArray<Belle2::TrackFitResult> tracks;
    for (const Belle2::TrackFitResult& track : tracks) {
      const ROOT::Math::XYZVector& trackPos = track.getPosition();
 
      double trackAngle = ROOT::Math::VectorUtil::Angle(trackPos, pos);
      if (trackAngle < angle) {
        B2DEBUG(20, "BelleFlagTracklAngle::" << trackAngle);
        return 1;
      }
    }
    return 0;
  }
 
 
  int BelleECLFlag(const Belle2::KLMCluster& cluster, const float angle = 0.26)
  {
    const ROOT::Math::XYZVector& pos = cluster.getClusterPosition();
    Belle2::StoreArray<Belle2::ECLCluster> eclclusters;
 
    for (const Belle2::ECLCluster& eclcluster : eclclusters) {
 
      const ROOT::Math::XYZVector& clusterPos = eclcluster.getClusterPosition();
 
      double clusterAngle = ROOT::Math::VectorUtil::Angle(clusterPos, pos);
      if (clusterAngle < angle) {
        B2DEBUG(20, "BelleFlagECLAngle::" << clusterAngle);
        return 1;
      }
    }
    return 0;
  }
 
  int mcParticleIsBeamBKG(const Belle2::MCParticle* part)
  {
    if (part == nullptr) {
      return 1;
    } else {
      return 0;
    }
  }
 
  int mcParticleIsKlong(Belle2::MCParticle* part)
  {
    unsigned int hirachy_counter = 0;
    if (mcParticleIsBeamBKG(part)) {
      return 0;
    }
    bool stop = false;
    while (!stop) {
      ++hirachy_counter;
      if (part -> getPDG() == Const::Klong.getPDGCode()) {
        return hirachy_counter;
      }
      if ((part -> getMother() == nullptr)) {
        stop = true;
      } else {
        part = part -> getMother();
      }
    }
    return 0;
  }
 
  bool isKLMClusterSignal(const Belle2::KLMCluster& cluster, float mcWeigthCut = 0.66)
  {
    const auto mcParticleWeightPair = cluster.getRelatedToWithWeight<Belle2::MCParticle>();
    Belle2::MCParticle* part        = mcParticleWeightPair.first;
    if (!part) {return false; }
    float mcWeight = mcParticleWeightPair.second;
    if (mcParticleIsKlong(part) && (mcWeight > mcWeigthCut)) {
      return true;
    } else {
      return false;
    }
  }
 
  bool isECLClusterSignal(const Belle2::ECLCluster& cluster, float mcWeigthCut = 0.66)
  {
    const auto mcParticleWeightPair = cluster.getRelatedToWithWeight<Belle2::MCParticle>();
    Belle2::MCParticle* part        = mcParticleWeightPair.first;
    if (!part) {return false; }
    float mcWeight = mcParticleWeightPair.second;
    if (mcParticleIsKlong(part) && (mcWeight > mcWeigthCut)) {
      return true;
    } else {
      return false;
    }
  }
 
  int isMCParticlePDG(Belle2::MCParticle* part, int pdg)
  {
    bool stop = false;
    while (!stop) {
      if (std::abs(part -> getPDG()) == pdg) {
        return true;
      }
      if ((part -> getMother() == nullptr)) {
        stop = true;
      } else {
        part = part -> getMother();
      }
    }
    return false;
  }
 
 
  int getPrimaryPDG(Belle2::MCParticle* part)
  {
 
    if (mcParticleIsBeamBKG(part)) {
      return -999;
    }
 
    bool stop = false;
    while (!stop) {
      if (isMCParticlePDG(part, Const::Klong.getPDGCode())) {
        return Const::Klong.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::Kshort.getPDGCode())) {
        return Const::Kshort.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::kaon.getPDGCode())) {
        return Const::kaon.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::neutron.getPDGCode())) {
        return Const::neutron.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::proton.getPDGCode())) {
        return Const::proton.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::pion.getPDGCode())) {
        return Const::pion.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::pi0.getPDGCode())) {
        return Const::pi0.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::muon.getPDGCode())) {
        return Const::muon.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::electron.getPDGCode())) {
        return Const::electron.getPDGCode();
      }
      if (isMCParticlePDG(part, Const::photon.getPDGCode())) {
        return Const::photon.getPDGCode();
      }
      if ((part -> getMother() == nullptr)) {
        stop = true;
      } else {
        part = part -> getMother();
      }
    }
    return part ->getPDG();
  }
 
  std::pair<Belle2::ECLCluster*, double> findClosestECLCluster(const ROOT::Math::XYZVector& klmClusterPosition,
      const Belle2::ECLCluster::EHypothesisBit eclhypothesis = Belle2::ECLCluster::EHypothesisBit::c_neutralHadron)
  {
 
    Belle2::ECLCluster* closestECL = nullptr;
    double closestECLAngleDist = 1e10;
    Belle2::StoreArray<Belle2::ECLCluster> eclClusters;
 
    if (eclClusters.getEntries() > 0) {
      int index = 0;
      int indexOfClosestCluster = -1;
      for (Belle2::ECLCluster& eclcluster : eclClusters) {
 
        if (eclcluster.hasHypothesis(eclhypothesis)) {
 
          const ROOT::Math::XYZVector& eclclusterPos = eclcluster.getClusterPosition();
          double angularDist = ROOT::Math::VectorUtil::Angle(
                                 eclclusterPos, klmClusterPosition);
          if (angularDist < closestECLAngleDist) {
            closestECLAngleDist = angularDist;
            indexOfClosestCluster = index;
          }
        }
        ++index;
      }
      if (indexOfClosestCluster > -1)
        closestECL = eclClusters[indexOfClosestCluster];
    }
    return std::make_pair(closestECL, closestECLAngleDist);
  }
 
 
  std::tuple<const Belle2::KLMCluster*, double, double> findClosestKLMCluster(const ROOT::Math::XYZVector& klmClusterPosition)
  {
 
    Belle2::StoreArray<Belle2::KLMCluster> klmClusters;
    const Belle2::KLMCluster* closestKLM = nullptr;
    double closestKLMDist = 1e10;
    double avInterClusterDist = 0;
    double nKLMCluster = klmClusters.getEntries();
 
    if (nKLMCluster > 1) {
 
      unsigned int index = 0;
      unsigned int indexOfClosestCluster = 0;
      for (const Belle2::KLMCluster& nextCluster : klmClusters) {
 
        const ROOT::Math::XYZVector& nextClusterPos = nextCluster.getClusterPosition();
        const ROOT::Math::XYZVector& clustDistanceVec = nextClusterPos - klmClusterPosition;
 
        double nextClusterDist = clustDistanceVec.Mag2();
        avInterClusterDist = avInterClusterDist + nextClusterDist;
 
        if ((nextClusterDist < closestKLMDist) and not(nextClusterDist == 0)) {
          closestKLMDist = nextClusterDist ;
          indexOfClosestCluster = index;
        }
        ++index;
      }// for next_cluster
 
      closestKLM = klmClusters[indexOfClosestCluster];
      avInterClusterDist = avInterClusterDist / (1. * nKLMCluster);
    }
 
    return std::make_tuple(closestKLM, closestKLMDist, avInterClusterDist);
  }
 
 
  std::tuple<Belle2::RecoTrack*, double, std::unique_ptr<const ROOT::Math::XYZVector> > findClosestTrack(
    const ROOT::Math::XYZVector& clusterPosition,
    float cutAngle)
  {
    Belle2::StoreArray<Belle2::RecoTrack> genfitTracks;
    double oldDistance = 10000000;//dont wanna use infty cos that kills tmva...
    Belle2::RecoTrack* closestTrack = nullptr;
    ROOT::Math::XYZVector poca = ROOT::Math::XYZVector(0, 0, 0);
 
 
    for (Belle2::RecoTrack& track : genfitTracks) {
 
      try {
        genfit::MeasuredStateOnPlane state;
        genfit::MeasuredStateOnPlane state_for_cut;
        state_for_cut = track.getMeasuredStateOnPlaneFromFirstHit();
 
        // only use tracks that are close cos the extrapolation takes ages
        double angle = ROOT::Math::VectorUtil::Angle(clusterPosition, state_for_cut.getPos());
        if (angle < cutAngle) {
          state = track.getMeasuredStateOnPlaneFromLastHit();
          state.extrapolateToPoint(XYZToTVector(clusterPosition));
          const TVector3& position = state.getPos();
          const ROOT::Math::XYZVector trackPos(
            position.X(), position.Y(), position.Z());
 
          const ROOT::Math::XYZVector& distanceVecCluster = clusterPosition - trackPos;
          double newDistance = distanceVecCluster.Mag2();
 
          // overwrite old distance
          if (newDistance < oldDistance) {
            oldDistance = newDistance;
            closestTrack = &track;
            poca = trackPos;
          }
        }
      } catch (genfit::Exception& e) {
      }// try
    }// for gftrack
 
    if (not closestTrack) {
      return std::make_tuple(nullptr, oldDistance, std::unique_ptr<const ROOT::Math::XYZVector>(nullptr));
    } else {
      // actually this is fine because of the datastore
      // cppcheck-suppress returnDanglingLifetime
      return std::make_tuple(closestTrack, oldDistance, std::unique_ptr<const ROOT::Math::XYZVector>(new ROOT::Math::XYZVector(poca)));
    }
  }
}//end namespace