ParticleVertexFitterModule.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 <analysis/modules/ParticleVertexFitter/ParticleVertexFitterModule.h>
 
// framework aux
#include <framework/gearbox/Unit.h>
#include <framework/gearbox/Const.h>
#include <framework/logging/Logger.h>
#include <framework/particledb/EvtGenDatabasePDG.h>
 
// dataobjects
#include <analysis/dataobjects/Particle.h>
#include <analysis/dataobjects/Btube.h>
#include <mdst/dataobjects/V0.h>
 
// utilities
#include <analysis/utility/CLHEPToROOT.h>
#include <analysis/utility/PCmsLabTransform.h>
#include <analysis/utility/ParticleCopy.h>
#include <analysis/utility/ROOTToCLHEP.h>
 
// Magnetic field
#include <framework/geometry/BFieldManager.h>
 
// KFit
#include <analysis/VertexFitting/KFit/KFitConst.h>
#include <analysis/VertexFitting/KFit/MassFitKFit.h>
#include <analysis/VertexFitting/KFit/FourCFitKFit.h>
#include <analysis/VertexFitting/KFit/MassFourCFitKFit.h>
#include <analysis/VertexFitting/KFit/MassPointingVertexFitKFit.h>
#include <analysis/VertexFitting/KFit/MassVertexFitKFit.h>
#include <analysis/VertexFitting/KFit/VertexFitKFit.h>
#include <analysis/VertexFitting/KFit/MakeMotherKFit.h>
#include <analysis/VertexFitting/KFit/RecoilMassKFit.h>
 
// Rave
#include <analysis/VertexFitting/RaveInterface/RaveSetup.h>
#include <analysis/VertexFitting/RaveInterface/RaveVertexFitter.h>
#include <analysis/VertexFitting/RaveInterface/RaveKinematicVertexFitter.h>
 
#include <TVector.h>
#include <TRotation.h>
#include <TMath.h>
 
using namespace std;
using namespace Belle2;
 
 
//-----------------------------------------------------------------
//                 Register module
//-----------------------------------------------------------------
 
REG_MODULE(ParticleVertexFitter);
 
//-----------------------------------------------------------------
//                 Implementation
//-----------------------------------------------------------------
 
ParticleVertexFitterModule::ParticleVertexFitterModule() : Module(),
  m_Bfield(0)
{
  // set module description (e.g. insert text)
  setDescription("Vertex fitter for modular analysis");
  setPropertyFlags(c_ParallelProcessingCertified);
 
  // Add parameters
  addParam("listName", m_listName, "name of particle list", string(""));
  addParam("confidenceLevel", m_confidenceLevel,
           "Confidence level to accept the fit. Particle candidates with "
           "p-value less than confidenceLevel are removed from the particle "
           "list. If set to -1, all candidates are kept; if set to 0, "
           "the candidates failing the fit are removed.",
           0.001);
  addParam("vertexFitter", m_vertexFitter, "KFit or Rave", string("KFit"));
  addParam("fitType", m_fitType, "type of the kinematic fit (vertex, massvertex, mass)", string("vertex"));
  addParam("withConstraint", m_withConstraint,
           "additional constraint on vertex: ipprofile, iptube, mother, iptubecut, pointing, btube",
           string(""));
  addParam("decayString", m_decayString, "specifies which daughter particles are included in the kinematic fit", string(""));
  addParam("updateDaughters", m_updateDaughters, "true: update the daughters after the vertex fit", false);
  addParam("smearing", m_smearing, "smear IP tube width by given length", 0.002);
  addParam("recoilMass", m_recoilMass, "recoil invariant mass (GeV)", 0.);
  addParam("massConstraintList", m_massConstraintList,
           "Type::[int]. List of daughter particles to mass constrain with int = pdg code. (only for MassFourCKFit)", {});
}
 
void ParticleVertexFitterModule::initialize()
{
  // Particle list with name m_listName has to exist
  m_plist.isRequired(m_listName);
 
  // magnetic field
  m_Bfield = BFieldManager::getFieldInTesla(ROOT::Math::XYZVector(0, 0, 0)).Z();
 
  // RAVE setup
  if (m_vertexFitter == "Rave")
    analysis::RaveSetup::initialize(1, m_Bfield);
 
  B2DEBUG(1, "ParticleVertexFitterModule : magnetic field = " << m_Bfield);
 
 
  if (m_decayString != "")
    m_decaydescriptor.init(m_decayString);
 
  B2INFO("ParticleVertexFitter: Performing " << m_fitType << " fit on " << m_listName << " using " << m_vertexFitter);
  if (m_decayString != "")
    B2INFO("ParticleVertexFitter: Using specified decay string: " << m_decayString);
  if (m_withConstraint != "")
    B2INFO("ParticleVertexFitter: Additional " << m_withConstraint << " will be applied");
 
}
 
void ParticleVertexFitterModule::beginRun()
{
  // TODO: set magnetic field for each run
  // m_Bfield = BFieldManager::getFieldInTesla(ROOT::Math::XYZVector(0, 0, 0)).Z();
  // TODO: set IP spot size for each run
}
 
void ParticleVertexFitterModule::event()
{
  if (m_vertexFitter == "Rave")
    analysis::RaveSetup::initialize(1, m_Bfield);
 
  m_BeamSpotCenter = m_beamSpotDB->getIPPosition();
  m_beamSpotCov.ResizeTo(3, 3);
  if (m_withConstraint == "ipprofile") m_beamSpotCov = m_beamSpotDB->getCovVertex();
  if (m_withConstraint == "iptube") {
    if (m_smearing > 0 && m_vertexFitter == "KFit") {
      ParticleVertexFitterModule::smearBeamSpot(m_smearing);
    } else {
      ParticleVertexFitterModule::findConstraintBoost(2.);
    }
  }
  if (m_withConstraint == "iptubecut") {  // for development purpose only
    m_BeamSpotCenter = ROOT::Math::XYZVector(0.001, 0., .013);
    findConstraintBoost(0.03);
  }
  if ((m_vertexFitter == "Rave") && (m_withConstraint == "ipprofile" || m_withConstraint == "iptube"
                                     || m_withConstraint == "mother" || m_withConstraint == "iptubecut" || m_withConstraint == "btube"))
    analysis::RaveSetup::getInstance()->setBeamSpot(m_BeamSpotCenter, m_beamSpotCov);
 
  std::vector<unsigned int> toRemove;
  unsigned int nParticles = m_plist->getListSize();
 
  for (unsigned iPart = 0; iPart < nParticles; iPart++) {
    Particle* particle = m_plist->getParticle(iPart);
    m_hasCovMatrix = false;
    if (m_updateDaughters == true) {
      if (m_decayString.empty() || m_vertexFitter == "KFit")
        ParticleCopy::copyDaughters(particle);
      else B2ERROR("Daughters update works only when all daughters are selected. Daughters will not be updated");
    }
 
    if (m_withConstraint == "mother") {
      m_BeamSpotCenter = particle->getVertex();
      m_beamSpotCov = particle->getVertexErrorMatrix();
    }
 
    TMatrixFSym mother_errMatrix(7);
    mother_errMatrix = particle->getMomentumVertexErrorMatrix();
    for (int k = 0; k < 7; k++) {
      for (int j = 0; j < 7; j++) {
        if (mother_errMatrix[k][j] > 0) {
          m_hasCovMatrix = true;
        }
      }
    }
 
    bool hasTube = true;
    if (m_withConstraint == "btube") {
      Btube* Ver = particle->getRelatedTo<Btube>();
      if (!Ver) {
        hasTube = false;
        toRemove.push_back(particle->getArrayIndex());
      } else {
        m_BeamSpotCenter.SetXYZ(Ver->getTubeCenter()(0, 0), Ver->getTubeCenter()(1, 0), Ver->getTubeCenter()(2, 0));
        m_beamSpotCov = Ver->getTubeMatrix();
      }
    }
    bool ok = false;
    if (hasTube) {
      ok = doVertexFit(particle);
    }
    if (!ok)
      particle->setPValue(-1);
    if (particle->getPValue() < m_confidenceLevel)
      toRemove.push_back(particle->getArrayIndex());
 
  }
  m_plist->removeParticles(toRemove);
 
  //free memory allocated by rave. initialize() would be enough, except that we must clean things up before program end...
  if (m_vertexFitter == "Rave")
    analysis::RaveSetup::getInstance()->reset();
}
 
bool ParticleVertexFitterModule::doVertexFit(Particle* mother)
{
  // steering starts here
 
  if (m_Bfield == 0) {
    B2FATAL("ParticleVertexFitter: No magnetic field");
  }
 
  if (m_withConstraint != "ipprofile" &&
      m_withConstraint != "iptube" &&
      m_withConstraint != "mother" &&
      m_withConstraint != "iptubecut" &&
      m_withConstraint != "pointing" &&
      m_withConstraint != "btube" &&
      m_withConstraint != "")
    B2FATAL("ParticleVertexFitter: " << m_withConstraint << " ***invalid Constraint ");
 
  bool ok = false;
  // fits with KFit
  if (m_vertexFitter == "KFit") {
 
    if (m_decayString != "" and m_fitType != "vertex")
      B2FATAL("ParticleVertexFitter: KFit does not support yet selection of daughters via decay string except for vertex fit!");
 
    // vertex fit
    if (m_fitType == "vertex") {
      if (m_withConstraint == "ipprofile") {
        ok = doKVertexFit(mother, true, false);
      } else if (m_withConstraint == "iptube") {
        ok = doKVertexFit(mother, false, true);
      } else {
        ok = doKVertexFit(mother, false, false);
      }
    }
 
    // mass-constrained vertex fit
    if (m_fitType == "massvertex") {
      if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube" || m_withConstraint == "iptubecut") {
        B2FATAL("ParticleVertexFitter: Invalid options - mass-constrained fit using KFit does not work with iptube or ipprofile constraint.");
      } else if (m_withConstraint == "pointing") {
        ok = doKMassPointingVertexFit(mother);
      } else {
        ok = doKMassVertexFit(mother);
      }
    }
 
    // mass fit
    if (m_fitType == "mass") {
      if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube" || m_withConstraint == "iptubecut") {
        B2FATAL("ParticleVertexFitter: Invalid options - mass fit using KFit does not work with iptube or ipprofile constraint.");
      } else {
        ok = doKMassFit(mother);
      }
    }
 
    // four C fit
    if (m_fitType == "fourC") {
      if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube" || m_withConstraint == "iptubecut") {
        B2FATAL("ParticleVertexFitter: Invalid options - four C fit using KFit does not work with iptube or ipprofile constraint.");
      } else {
        ok = doKFourCFit(mother);
      }
    }
 
    // four mass C fit
    if (m_fitType == "massfourC") {
      if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube" || m_withConstraint == "iptubecut") {
        B2FATAL("ParticleVertexFitter: Invalid options - four C fit using KFit does not work with iptube or ipprofile constraint.");
      } else {
        ok = doKMassFourCFit(mother);
      }
    }
 
    // recoil mass C fit
    if (m_fitType == "recoilmass") {
      if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube" || m_withConstraint == "iptubecut") {
        B2FATAL("ParticleVertexFitter: Invalid options - recoil mass fit using KFit does not work with iptube or ipprofile constraint.");
      } else {
        ok = doKRecoilMassFit(mother);
      }
    }
 
    // invalid KFit fit type
    if (m_fitType != "vertex"
        && m_fitType != "massvertex"
        && m_fitType != "mass"
        && m_fitType != "fourC"
        && m_fitType != "massfourC"
        && m_fitType != "recoilmass")
      B2FATAL("ParticleVertexFitter: " << m_fitType << " ***invalid fit type for the vertex fitter ");
  }
 
  // fits using Rave
  if (m_vertexFitter == "Rave") {
    try {
      ok = doRaveFit(mother);
    } catch (const rave::CheckedFloatException&) {
      B2ERROR("Invalid inputs (nan/inf)?");
      ok = false;
    }
  }
 
  // invalid fitter
  if (m_vertexFitter != "KFit" && m_vertexFitter != "Rave")
    B2FATAL("ParticleVertexFitter: " << m_vertexFitter << " ***invalid vertex fitter ");
 
  if (!ok) return false;
 
  // steering ends here
 
  //if (mother->getPValue() < m_confidenceLevel) return false;
  return true;
 
}
 
bool ParticleVertexFitterModule::fillFitParticles(const Particle* mother, std::vector<const Particle*>& fitChildren,
                                                  std::vector<const Particle*>& twoPhotonChildren)
{
  if (m_decayString.empty()) {
    // if decayString is empty, just use all primary daughters
    for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
      const Particle* child = mother->getDaughter(ichild);
      // This if allows to skip the daughters, which cannot be used in the fits, particularly K_L0 from KLM.
      // Useful for fully-inclusive particles.
      if (mother->getProperty() == Particle::PropertyFlags::c_IsUnspecified and child->getPValue() < 0) {
        continue;
      }
      fitChildren.push_back(child);
    }
  } else {
    fitChildren = m_decaydescriptor.getSelectionParticles(mother);
  }
 
  auto itr = fitChildren.begin();
  while (itr != fitChildren.end()) {
    const Particle* child = *itr;
 
    if (child->getPValue() < 0) {
      B2WARNING("Daughter with PDG code " << child->getPDGCode() << " does not have a valid error matrix.");
      return false; // error matrix not valid
    }
    bool isTwoPhotonParticle = false;
    if (m_hasCovMatrix == false) {
      if (child->getPDGCode() == Const::pi0.getPDGCode() or child->getPDGCode() == 221) { // pi0 or eta
        if (child->getNDaughters() == 2) {
          if (child->getDaughter(0)->getPDGCode() == Const::photon.getPDGCode()
              && child->getDaughter(1)->getPDGCode() == Const::photon.getPDGCode()) {
            isTwoPhotonParticle = true;
          }
        }
      }
    }
    if (isTwoPhotonParticle) {
      // move children from fitChildren to twoPhotonChildren
      twoPhotonChildren.push_back(child);
      itr = fitChildren.erase(itr);
    } else {
      itr++;
    }
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::fillNotFitParticles(const Particle* mother, std::vector<const Particle*>& notFitChildren,
                                                     const std::vector<const Particle*>& fitChildren)
{
  if (fitChildren.empty())
    B2WARNING("[ParticleVertexFitterModule::fillNotFitParticles] fitChildren is empty! Please call fillFitParticles firstly");
  if (!notFitChildren.empty())
    B2WARNING("[ParticleVertexFitterModule::fillNotFitParticles] notFitChildren is NOT empty!"
              << " The function should be called only once");
 
  if (m_decayString.empty())
    // if decayString is empty, just use all primary daughters
    return true;
 
  std::function<bool(const Particle*)> funcCheckInFit =
  [&funcCheckInFit, &notFitChildren, fitChildren](const Particle * part) {
 
    // check if the given particle in fitChildren
    // if it is included, return true
    if (std::find(fitChildren.begin(), fitChildren.end(), part) != fitChildren.end())
      return true;
 
    // if not, firstly check if particle has children
    if (part->getNDaughters() == 0)
      // if it has no children (=final-state-particle), return false
      return false;
 
    // here, the given particle is not in fitChildren and has children
    bool isAnyChildrenInFit = false;
    vector<const Particle*> notFitChildren_tmp;
    for (unsigned ichild = 0; ichild < part->getNDaughters(); ichild++) {
      // call funcCheckInFit recursively for all children
      const Particle* child = part->getDaughter(ichild);
      bool isChildrenInFit = funcCheckInFit(child);
      isAnyChildrenInFit = isChildrenInFit or isAnyChildrenInFit;
 
      // if the child is not in fitChildren, fill the child in a temporary vector
      if (!isChildrenInFit)
        notFitChildren_tmp.push_back(child);
    }
 
    // if there are a sister in fitChildren, the children in the temporary vector will be filled in notFitChildren
    if (isAnyChildrenInFit)
      notFitChildren.insert(notFitChildren.end(), notFitChildren_tmp.begin(), notFitChildren_tmp.end());
 
    // if no children in fitChildren, the given particle should be filled instead of all children.
 
    return isAnyChildrenInFit;
  };
 
 
  // call funcCheckInFit for all primary children
  for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
    const Particle* child = mother->getDaughter(ichild);
    bool isGivenParticleOrAnyChildrenInFit = funcCheckInFit(child);
    if (!isGivenParticleOrAnyChildrenInFit)
      notFitChildren.push_back(child);
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::redoTwoPhotonDaughterMassFit(Particle* postFit, const Particle* preFit,
    const analysis::VertexFitKFit& kv)
{
  // TODO: something like setGammaError is necessary
  // this is just workaround for the moment
 
  const Particle* g1Orig = preFit->getDaughter(0);
  const Particle* g2Orig = preFit->getDaughter(1);
  Particle g1Temp(g1Orig->get4Vector(), 22);
  Particle g2Temp(g2Orig->get4Vector(), 22);
 
  TMatrixFSym g1ErrMatrix = g1Orig->getMomentumVertexErrorMatrix();
  TMatrixFSym g2ErrMatrix = g2Orig->getMomentumVertexErrorMatrix();
 
  ROOT::Math::XYZVector pos(kv.getVertex().x(), kv.getVertex().y(), kv.getVertex().z());
  CLHEP::HepSymMatrix posErrorMatrix = kv.getVertexError();
 
  TMatrixFSym errMatrix(3);
  for (int i = 0; i < 3; i++)
    for (int j = 0; j < 3; j++)
      errMatrix(i, j) = posErrorMatrix[i][j];
 
  g1ErrMatrix.SetSub(4, errMatrix);
  g2ErrMatrix.SetSub(4, errMatrix);
 
  g1Temp.updateMomentum(g1Orig->get4Vector(), pos, g1ErrMatrix, 1.0);
  g2Temp.updateMomentum(g2Orig->get4Vector(), pos, g2ErrMatrix, 1.0);
 
  // perform the mass fit for the two-photon particle
  analysis::MassFitKFit km;
  km.setMagneticField(m_Bfield);
 
  km.addParticle(&g1Temp);
  km.addParticle(&g2Temp);
 
  km.setVertex(kv.getVertex());
  km.setVertexError(kv.getVertexError());
  km.setInvariantMass(preFit->getPDGMass());
 
  int err = km.doFit();
  if (err != 0) {
    return false;
  }
 
  // The update of the daughters is disabled for this mass fit.
  bool updateDaughters = m_updateDaughters;
  m_updateDaughters = false;
  bool ok = makeKMassMother(km, postFit);
  m_updateDaughters = updateDaughters;
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKVertexFit(Particle* mother, bool ipProfileConstraint, bool ipTubeConstraint)
{
  if ((mother->getNDaughters() < 2 && !ipTubeConstraint) || mother->getNDaughters() < 1) return false;
 
  std::vector<const Particle*> fitChildren;
  std::vector<const Particle*> twoPhotonChildren;
  bool validChildren = fillFitParticles(mother, fitChildren, twoPhotonChildren);
 
  if (!validChildren)
    return false;
 
  std::vector<const Particle*> notFitChildren;
  fillNotFitParticles(mother, notFitChildren, fitChildren);
 
 
  if (twoPhotonChildren.size() > 1) {
    B2FATAL("[ParticleVertexFitterModule::doKVertexFit] Vertex fit using KFit does not support fit with multiple particles decaying to two photons like pi0 (yet).");
  }
 
  if ((fitChildren.size() < 2 && !ipTubeConstraint) || fitChildren.size() < 1) {
    B2WARNING("[ParticleVertexFitterModule::doKVertexFit] Number of particles with valid error matrix entering the vertex fit using KFit is too low.");
    return false;
  }
 
  // Initialise the Fitter
  analysis::VertexFitKFit kv;
  kv.setMagneticField(m_Bfield);
 
  if (mother->getV0()) {
    kv.setInitialVertex(mother->getV0()->getFittedVertexPosition());
  }
 
  for (auto& child : fitChildren)
    kv.addParticle(child);
 
  if (ipProfileConstraint)
    addIPProfileToKFit(kv);
 
  if (ipTubeConstraint)
    addIPTubeToKFit(kv);
 
  // Perform vertex fit using only the particles with valid error matrices
  int err = kv.doFit();
  if (err != 0)
    return false;
 
  double chi2_track = getChi2TracksLBoost(kv);
  unsigned track_count = kv.getTrackCount();
  mother->writeExtraInfo("chiSquared_trackL", chi2_track);
  mother->writeExtraInfo("kFit_nTracks", track_count);
 
  bool ok = false;
  if (twoPhotonChildren.size() == 0)
    // in the case daughters do not include pi0 - this is it (fit done)
    ok = makeKVertexMother(kv, mother);
  else if (twoPhotonChildren.size() == 1) {
    // there is a daughter reconstructed from two photons so without position information
    // 1. determine vertex based on all other valid daughters
    // 2. set position and error matrix of two-photon daughter to previously determined vertex
    // 3. redo the fit using all particles (including two-photon particle this time)
 
    const Particle* twoPhotonDaughter = twoPhotonChildren[0];
    Particle fixedTwoPhotonDaughter(twoPhotonDaughter->get4Vector(), twoPhotonDaughter->getPDGCode());
    ok = redoTwoPhotonDaughterMassFit(&fixedTwoPhotonDaughter, twoPhotonDaughter, kv);
    if (!ok)
      return false;
 
    // finally perform the fit using all daughter particles
    analysis::VertexFitKFit kv2;
    kv2.setMagneticField(m_Bfield);
 
    for (auto& child : fitChildren)
      kv2.addParticle(child);
 
    kv2.addParticle(&fixedTwoPhotonDaughter);
 
    if (ipProfileConstraint)
      addIPProfileToKFit(kv2);
 
    err = kv2.doFit();
 
    if (err != 0)
      return false;
 
    ok = makeKVertexMother(kv2, mother);
  }
 
  // update 4-vector using not-fit-particles
  ROOT::Math::PxPyPzEVector total4Vector(mother->get4Vector());
  for (auto& child : notFitChildren)
    total4Vector += child->get4Vector();
  mother->set4Vector(total4Vector);
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKMassVertexFit(Particle* mother)
{
  if (mother->getNDaughters() < 2) return false;
 
  std::vector<const Particle*> fitChildren;
  std::vector<const Particle*> twoPhotonChildren;
  bool validChildren = fillFitParticles(mother, fitChildren, twoPhotonChildren);
 
  if (!validChildren)
    return false;
 
  if (twoPhotonChildren.size() > 1) {
    B2FATAL("[ParticleVertexFitterModule::doKVertexFit] MassVertex fit using KFit does not support fit with multiple particles decaying to two photons like pi0 (yet).");
  }
 
  if (fitChildren.size() < 2) {
    B2WARNING("[ParticleVertexFitterModule::doKVertexFit] Number of particles with valid error matrix entering the vertex fit using KFit is less than 2.");
    return false;
  }
 
  bool ok = false;
  if (twoPhotonChildren.size() == 0) {
    // Initialise the Fitter
    analysis::MassVertexFitKFit kmv;
    kmv.setMagneticField(m_Bfield);
 
    if (mother->getV0()) {
      HepPoint3D V0vertex_heppoint(mother->getV0()->getFittedVertexX(),
                                   mother->getV0()->getFittedVertexY(),
                                   mother->getV0()->getFittedVertexZ());
      kmv.setInitialVertex(V0vertex_heppoint);
    }
 
    for (auto child : fitChildren)
      kmv.addParticle(child);
 
    kmv.setInvariantMass(mother->getPDGMass());
    int err = kmv.doFit();
    if (err != 0)
      return false;
 
    // in the case daughters do not include particles with two photon daughters like pi0 - this is it (fit done)
    ok = makeKMassVertexMother(kmv, mother);
  } else if (twoPhotonChildren.size() == 1) {
    // there is a daughter reconstructed from two photons so without position information
    // 1. determine vertex based on all other valid daughters
    // 2. set position and error matrix of two-photon daughter to previously determined vertex
    // 3. redo the fit using all particles (including two-photon particle this time)
 
    analysis::VertexFitKFit kv;
    kv.setMagneticField(m_Bfield);
 
    for (auto child : fitChildren)
      kv.addParticle(child);
 
    // Perform vertex fit using only the particles with valid error matrices
    int err = kv.doFit();
    if (err != 0)
      return false;
 
    const Particle* twoPhotonDaughter = twoPhotonChildren[0];
    Particle fixedTwoPhotonDaughter(twoPhotonDaughter->get4Vector(), twoPhotonDaughter->getPDGCode());
    ok = redoTwoPhotonDaughterMassFit(&fixedTwoPhotonDaughter, twoPhotonDaughter, kv);
    if (!ok)
      return false;
 
    // finally perform the fit using all daughter particles
    analysis::MassVertexFitKFit kmv2;
    kmv2.setMagneticField(m_Bfield);
 
    for (auto child : fitChildren)
      kmv2.addParticle(child);
    kmv2.addParticle(&fixedTwoPhotonDaughter);
 
    kmv2.setInvariantMass(mother->getPDGMass());
    err = kmv2.doFit();
 
    if (err != 0)
      return false;
 
    ok = makeKMassVertexMother(kmv2, mother);
  }
 
  return ok;
 
}
 
bool ParticleVertexFitterModule::doKMassPointingVertexFit(Particle* mother)
{
  if (!(mother->hasExtraInfo("prodVertX") && mother->hasExtraInfo("prodVertY") && mother->hasExtraInfo("prodVertZ"))) {
    return false;
  }
 
  if (mother->getNDaughters() < 2) return false;
 
  std::vector<const Particle*> fitChildren;
  std::vector<const Particle*> twoPhotonChildren;
  bool validChildren = fillFitParticles(mother, fitChildren, twoPhotonChildren);
 
  if (!validChildren)
    return false;
 
  if (twoPhotonChildren.size() > 0) {
    B2FATAL("[ParticleVertexFitterModule::doKMassPointingVertexFit] MassPointingVertex fit using KFit does not support fit with two-photon daughters (yet).");
  }
 
  if (fitChildren.size() < 2) {
    B2WARNING("[ParticleVertexFitterModule::doKMassPointingVertexFit] Number of particles with valid error matrix entering the vertex fit using KFit is less than 2.");
    return false;
  }
 
  bool ok = false;
  // Initialise the Fitter
  analysis::MassPointingVertexFitKFit kmpv;
  kmpv.setMagneticField(m_Bfield);
 
  for (auto child : fitChildren)
    kmpv.addParticle(child);
 
  kmpv.setInvariantMass(mother->getPDGMass());
  HepPoint3D productionVertex(mother->getExtraInfo("prodVertX"),
                              mother->getExtraInfo("prodVertY"),
                              mother->getExtraInfo("prodVertZ"));
  kmpv.setProductionVertex(productionVertex);
  int err = kmpv.doFit();
  if (err != 0) return false;
 
  ok = makeKMassPointingVertexMother(kmpv, mother);
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKMassFit(Particle* mother)
{
  if (mother->getNDaughters() < 2) return false;
 
  analysis::MassFitKFit km;
  km.setMagneticField(m_Bfield);
 
  for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
    const Particle* child = mother->getDaughter(ichild);
 
    if (child->getPValue() < 0) return false; // error matrix not valid
 
    km.addParticle(child);
  }
 
  // apply mass constraint
  km.setInvariantMass(mother->getPDGMass());
 
  int err = km.doFit();
 
  if (err != 0) return false;
 
  bool ok = makeKMassMother(km, mother);
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKFourCFit(Particle* mother)
{
  if (mother->getNDaughters() < 2) return false;
 
  analysis::FourCFitKFit kf;
  kf.setMagneticField(m_Bfield);
 
  for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
    const Particle* child = mother->getDaughter(ichild);
 
    if (child->getNDaughters() > 0) {
      bool err = addChildofParticletoKFit(kf, child);
      if (!err) return false;
    } else {
      if (child->getPValue() < 0) return false; // error matrix not valid
 
      kf.addParticle(child);
    }
  }
 
  // apply four momentum constraint
  PCmsLabTransform T;
  kf.setFourMomentum(T.getBeamFourMomentum());
 
  int err = kf.doFit();
 
  if (err != 0) return false;
 
  bool ok = makeKFourCMother(kf, mother);
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKMassFourCFit(Particle* mother)
{
  if (mother->getNDaughters() < 2) return false;
 
  analysis::MassFourCFitKFit kf;
  kf.setMagneticField(m_Bfield);
 
  for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
    const Particle* child = mother->getDaughter(ichild);
 
    if (child->getNDaughters() > 0) {
      bool massconstraint = std::find(m_massConstraintList.begin(), m_massConstraintList.end(),
                                      std::abs(child->getPDGCode())) != m_massConstraintList.end();
      std::vector<unsigned> childId;
      bool err = addChildofParticletoMassKFit(kf, child, childId);
      if (massconstraint) kf.addMassConstraint(child->getPDGMass(), childId);
      if (!err) return false;
    } else {
      if (child->getPValue() < 0) return false; // error matrix not valid
      kf.addParticle(child);
    }
  }
 
  // apply four momentum constraint
  PCmsLabTransform T;
  kf.setFourMomentum(T.getBeamFourMomentum());
 
  int err = kf.doFit();
 
  if (err != 0) return false;
 
  bool ok = makeMassKFourCMother(kf, mother);
 
  return ok;
}
 
bool ParticleVertexFitterModule::doKRecoilMassFit(Particle* mother)
{
  analysis::RecoilMassKFit kf;
  kf.setMagneticField(m_Bfield);
 
  for (unsigned ichild = 0; ichild < mother->getNDaughters(); ichild++) {
    const Particle* child = mother->getDaughter(ichild);
 
    if (child->getPValue() < 0) return false; // error matrix not valid
 
    kf.addParticle(child);
  }
 
  // apply four momentum constraint
  PCmsLabTransform T;
  kf.setFourMomentum(T.getBeamFourMomentum());
 
  // apply recoil mass constraint
  kf.setRecoilMass(m_recoilMass);
 
  int err = kf.doFit();
 
  if (err != 0) return false;
 
  bool ok = makeKRecoilMassMother(kf, mother);
 
  return ok;
}
 
bool ParticleVertexFitterModule::makeKVertexMother(analysis::VertexFitKFit& kv,
                                                   Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kv.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    unsigned track_count = kv.getTrackCount();
    if (daughters.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughters[iChild]->getCharge();
      double dx = kv.getVertex().x() - kv.getTrackPosition(iChild).x();
      double dy = kv.getVertex().y() - kv.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(kv.getTrackMomentum(iChild).x() - a * dy,
                                         kv.getTrackMomentum(iChild).y() + a * dx,
                                         kv.getTrackMomentum(iChild).z(),
                                         kv.getTrackMomentum(iChild).t());
      daughters[iChild]->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughters[iChild]->setVertex(
        CLHEPToROOT::getXYZVector(kv.getTrackPosition(iChild)));
      daughters[iChild]->setMomentumVertexErrorMatrix(
        CLHEPToROOT::getTMatrixFSym(kv.getTrackError(iChild)));
    }
 
  } else if (m_updateDaughters == true) { // if decayString is not empty
    // first, update only the fit children
    std::vector<const Particle*> fitChildren = m_decaydescriptor.getSelectionParticles(mother);
 
    unsigned track_count = kv.getTrackCount();
    if (fitChildren.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      auto daughter = const_cast<Particle*>(fitChildren[iChild]);
 
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughter->getCharge();
      double dx = kv.getVertex().x() - kv.getTrackPosition(iChild).x();
      double dy = kv.getVertex().y() - kv.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(kv.getTrackMomentum(iChild).x() - a * dy,
                                         kv.getTrackMomentum(iChild).y() + a * dx,
                                         kv.getTrackMomentum(iChild).z(),
                                         kv.getTrackMomentum(iChild).t());
      daughter->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughter->setVertex(CLHEPToROOT::getXYZVector(kv.getTrackPosition(iChild)));
      daughter->setMomentumVertexErrorMatrix(CLHEPToROOT::getTMatrixFSym(kv.getTrackError(iChild)));
    }
 
    // then, update other particles that have a fit-child in decay
    std::function<bool(Particle*)> funcUpdateMomentum =
    [&funcUpdateMomentum, fitChildren](Particle * part) {
 
      if (part->getNDaughters() == 0) {
        // check if part is included in fitChildren
        if (std::find(fitChildren.begin(), fitChildren.end(), part) != fitChildren.end())
          return true;
        else
          return false;
      }
 
      bool includeFitChildren = false;
 
      // Update daughters' momentum
      for (auto daughter : part->getDaughters())
        includeFitChildren = funcUpdateMomentum(daughter) || includeFitChildren;
 
      if (includeFitChildren) {
        // Using updated daughters, update part's momentum
        ROOT::Math::PxPyPzEVector sum4Vector;
        for (auto daughter : part->getDaughters())
          sum4Vector += daughter->get4Vector();
 
        part->set4VectorDividingByMomentumScaling(sum4Vector);
      }
 
      return includeFitChildren;
    };
 
    // Update all daughters
    for (auto daughter : mother->getDaughters())
      funcUpdateMomentum(daughter);
 
  }
 
 
  return true;
}
 
bool ParticleVertexFitterModule::makeKMassVertexMother(analysis::MassVertexFitKFit& kmv,
                                                       Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kmv.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    unsigned track_count = kmv.getTrackCount();
    if (daughters.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughters[iChild]->getCharge();
      double dx = kmv.getVertex().x() - kmv.getTrackPosition(iChild).x();
      double dy = kmv.getVertex().y() - kmv.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(kmv.getTrackMomentum(iChild).x() - a * dy,
                                         kmv.getTrackMomentum(iChild).y() + a * dx,
                                         kmv.getTrackMomentum(iChild).z(),
                                         kmv.getTrackMomentum(iChild).t());
      daughters[iChild]->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughters[iChild]->setVertex(
        CLHEPToROOT::getXYZVector(kmv.getTrackPosition(iChild)));
      daughters[iChild]->setMomentumVertexErrorMatrix(
        CLHEPToROOT::getTMatrixFSym(kmv.getTrackError(iChild)));
    }
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::makeKMassPointingVertexMother(analysis::MassPointingVertexFitKFit& kmpv,
    Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kmpv.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError) {
    return false;
  }
 
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    unsigned track_count = kmpv.getTrackCount();
    if (daughters.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughters[iChild]->getCharge();
      double dx = kmpv.getVertex().x() - kmpv.getTrackPosition(iChild).x();
      double dy = kmpv.getVertex().y() - kmpv.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(kmpv.getTrackMomentum(iChild).x() - a * dy,
                                         kmpv.getTrackMomentum(iChild).y() + a * dx,
                                         kmpv.getTrackMomentum(iChild).z(),
                                         kmpv.getTrackMomentum(iChild).t());
      daughters[iChild]->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughters[iChild]->setVertex(
        CLHEPToROOT::getXYZVector(kmpv.getTrackPosition(iChild)));
      daughters[iChild]->setMomentumVertexErrorMatrix(
        CLHEPToROOT::getTMatrixFSym(kmpv.getTrackError(iChild)));
    }
  }
 
  return true;
}
 
 
bool ParticleVertexFitterModule::makeKMassMother(analysis::MassFitKFit& km,
                                                 Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = km.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    unsigned track_count = km.getTrackCount();
    if (daughters.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughters[iChild]->getCharge();
      double dx = km.getVertex().x() - km.getTrackPosition(iChild).x();
      double dy = km.getVertex().y() - km.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(km.getTrackMomentum(iChild).x() - a * dy,
                                         km.getTrackMomentum(iChild).y() + a * dx,
                                         km.getTrackMomentum(iChild).z(),
                                         km.getTrackMomentum(iChild).t());
      daughters[iChild]->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughters[iChild]->setVertex(
        CLHEPToROOT::getXYZVector(km.getTrackPosition(iChild)));
      daughters[iChild]->setMomentumVertexErrorMatrix(
        CLHEPToROOT::getTMatrixFSym(km.getTrackError(iChild)));
    }
  }
 
  return true;
}
 
 
 
bool ParticleVertexFitterModule::makeKFourCMother(analysis::FourCFitKFit& kf, Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kf.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  mother->addExtraInfo("FourCFitProb", kf.getCHIsq());
  mother->addExtraInfo("FourCFitChi2", kf.getNDF());
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    const unsigned nd = daughters.size();
    unsigned l = 0;
    std::vector<std::vector<unsigned>> pars;
    pars.reserve(nd);
    std::vector<Particle*> allparticles;
    allparticles.reserve(nd);
    for (unsigned ichild = 0; ichild < nd; ichild++) {
      const Particle* daughter = mother->getDaughter(ichild);
      std::vector<unsigned> pard;
      if (daughter->getNDaughters() > 0) {
        updateMapOfTrackAndDaughter(l, pars, pard, allparticles, daughter);
        pars.push_back(std::move(pard));
        allparticles.push_back(daughters[ichild]);
      } else {
        pard.push_back(l);
        pars.push_back(std::move(pard));
        allparticles.push_back(daughters[ichild]);
        l++;
      }
    }
 
    unsigned track_count = kf.getTrackCount();
    if (l != track_count)
      return false;
 
    for (unsigned iDaug = 0; iDaug < allparticles.size(); iDaug++) {
      ROOT::Math::PxPyPzEVector childMoms;
      ROOT::Math::XYZVector childPoss;
      TMatrixFSym childErrMatrixs(7);
      for (unsigned int iChild : pars[iDaug]) {
        childMoms = childMoms +
                    CLHEPToROOT::getLorentzVector(
                      kf.getTrackMomentum(iChild));
        childPoss = childPoss +
                    CLHEPToROOT::getXYZVector(
                      kf.getTrackPosition(iChild));
        TMatrixFSym childErrMatrix =
          CLHEPToROOT::getTMatrixFSym(kf.getTrackError(iChild));
        childErrMatrixs = childErrMatrixs + childErrMatrix;
      }
      allparticles[iDaug]->set4Vector(childMoms);
      allparticles[iDaug]->setVertex(childPoss);
      allparticles[iDaug]->setMomentumVertexErrorMatrix(childErrMatrixs);
    }
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::makeMassKFourCMother(analysis::MassFourCFitKFit& kf, Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kf.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  mother->addExtraInfo("MassFourCFitProb", TMath::Prob(kf.getCHIsq(), kf.getNDF()));
  mother->addExtraInfo("MassFourCFitChi2", kf.getCHIsq());
  mother->addExtraInfo("MassFourCFitNDF", kf.getNDF());
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    const unsigned nd = daughters.size();
    unsigned l = 0;
    std::vector<std::vector<unsigned>> pars;
    pars.reserve(nd);
    std::vector<Particle*> allparticles;
    allparticles.reserve(nd);
    for (unsigned ichild = 0; ichild < nd; ichild++) {
      const Particle* daughter = mother->getDaughter(ichild);
      std::vector<unsigned> pard;
      if (daughter->getNDaughters() > 0) {
        updateMapOfTrackAndDaughter(l, pars, pard, allparticles, daughter);
        pars.push_back(std::move(pard));
        allparticles.push_back(daughters[ichild]);
      } else {
        pard.push_back(l);
        pars.push_back(std::move(pard));
        allparticles.push_back(daughters[ichild]);
        l++;
      }
    }
 
    unsigned track_count = kf.getTrackCount();
    if (l != track_count)
      return false;
 
    for (unsigned iDaug = 0; iDaug < allparticles.size(); iDaug++) {
      ROOT::Math::PxPyPzEVector childMoms;
      ROOT::Math::XYZVector childPoss;
      TMatrixFSym childErrMatrixs(7);
      for (unsigned int iChild : pars[iDaug]) {
        childMoms = childMoms +
                    CLHEPToROOT::getLorentzVector(
                      kf.getTrackMomentum(iChild));
        childPoss = childPoss +
                    CLHEPToROOT::getXYZVector(
                      kf.getTrackPosition(iChild));
        TMatrixFSym childErrMatrix =
          CLHEPToROOT::getTMatrixFSym(kf.getTrackError(iChild));
        childErrMatrixs = childErrMatrixs + childErrMatrix;
      }
      allparticles[iDaug]->set4Vector(childMoms);
      allparticles[iDaug]->setVertex(childPoss);
      allparticles[iDaug]->setMomentumVertexErrorMatrix(childErrMatrixs);
    }
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::makeKRecoilMassMother(analysis::RecoilMassKFit& kf, Particle* mother)
{
  enum analysis::KFitError::ECode fitError;
  fitError = kf.updateMother(mother);
  if (fitError != analysis::KFitError::kNoError)
    return false;
  mother->addExtraInfo("RecoilMassFitProb", TMath::Prob(kf.getCHIsq(), kf.getNDF()));
  mother->addExtraInfo("RecoilMassFitChi2", kf.getCHIsq());
  mother->addExtraInfo("RecoilMassFitNDF", kf.getNDF());
  if (m_decayString.empty() && m_updateDaughters == true) {
    // update daughter momenta as well
    // the order of daughters in the *fitter is the same as in the mother Particle
 
    std::vector<Particle*> daughters = mother->getDaughters();
 
    unsigned track_count = kf.getTrackCount();
    if (daughters.size() != track_count)
      return false;
 
    for (unsigned iChild = 0; iChild < track_count; iChild++) {
      double a = -1 * Const::speedOfLight * 1e-4 * m_Bfield * daughters[iChild]->getCharge();
      double dx = kf.getVertex().x() - kf.getTrackPosition(iChild).x();
      double dy = kf.getVertex().y() - kf.getTrackPosition(iChild).y();
 
      ROOT::Math::PxPyPzEVector i4Vector(kf.getTrackMomentum(iChild).x() - a * dy,
                                         kf.getTrackMomentum(iChild).y() + a * dx,
                                         kf.getTrackMomentum(iChild).z(),
                                         kf.getTrackMomentum(iChild).t());
      daughters[iChild]->set4VectorDividingByMomentumScaling(i4Vector);
 
      daughters[iChild]->setVertex(
        CLHEPToROOT::getXYZVector(kf.getTrackPosition(iChild)));
      daughters[iChild]->setMomentumVertexErrorMatrix(
        CLHEPToROOT::getTMatrixFSym(kf.getTrackError(iChild)));
    }
  }
 
  return true;
}
 
 
void ParticleVertexFitterModule::updateMapOfTrackAndDaughter(unsigned& l,  std::vector<std::vector<unsigned>>& pars,
    std::vector<unsigned>& parm, std::vector<Particle*>&  allparticles, const Particle* daughter)
{
  std::vector <Particle*> daughters = daughter->getDaughters();
  for (unsigned ichild = 0; ichild < daughter->getNDaughters(); ichild++) {
    const Particle* child = daughter->getDaughter(ichild);
    std::vector<unsigned> pard;
    if (child->getNDaughters() > 0) {
      updateMapOfTrackAndDaughter(l, pars, pard, allparticles, child);
      parm.insert(parm.end(), pard.begin(), pard.end());
      pars.push_back(pard);
      allparticles.push_back(daughters[ichild]);
    } else  {
      pard.push_back(l);
      parm.push_back(l);
      pars.push_back(pard);
      allparticles.push_back(daughters[ichild]);
      l++;
    }
  }
}
 
 
bool ParticleVertexFitterModule::doRaveFit(Particle* mother)
{
  if ((m_decayString.empty() ||
       (m_withConstraint == "" && m_fitType != "mass")) && mother->getNDaughters() < 2) return false;
  if (m_withConstraint == "") analysis::RaveSetup::getInstance()->unsetBeamSpot();
  if (m_withConstraint == "ipprofile" || m_withConstraint == "iptube"  || m_withConstraint == "mother"
      || m_withConstraint == "iptubecut" || m_withConstraint == "btube")
    analysis::RaveSetup::getInstance()->setBeamSpot(m_BeamSpotCenter, m_beamSpotCov);
 
  analysis::RaveKinematicVertexFitter rf;
  if (m_fitType == "mass") rf.setVertFit(false);
 
  if (m_decayString.empty()) {
    rf.addMother(mother);
  } else {
    std::vector<const Particle*> tracksVertex = m_decaydescriptor.getSelectionParticles(mother);
    std::vector<std::string> tracksName = m_decaydescriptor.getSelectionNames();
 
    if (allSelectedDaughters(mother, tracksVertex)) {
      for (auto& itrack : tracksVertex) {
        if (itrack != mother) rf.addTrack(itrack);
      }
      rf.setMother(mother);
    } else {
 
      analysis::RaveKinematicVertexFitter rsf;
      bool mothSel = false;
      int nTrk = 0;
      for (unsigned itrack = 0; itrack < tracksVertex.size(); itrack++) {
        if (tracksVertex[itrack] != mother) {
          rsf.addTrack(tracksVertex[itrack]);
          B2DEBUG(1, "ParticleVertexFitterModule: Adding particle " << tracksName[itrack] << " to vertex fit ");
          nTrk++;
        }
        if (tracksVertex[itrack] == mother) mothSel = true;
      }
 
 
      // Fit one particle constrained to originate from the beam spot
      bool mothIPfit = false;
      if (tracksVertex.size() == 1 && mothSel == true && m_withConstraint != "" && nTrk == 0) {
        rsf.addTrack(tracksVertex[0]);
        if (tracksVertex[0] != mother)
          B2FATAL("ParticleVertexFitterModule: FATAL Error in IP constrained mother fit");
        nTrk++;
        mothIPfit = true;
      }
 
 
      ROOT::Math::XYZVector pos;
      TMatrixDSym RerrMatrix(3);
      int nvert = 0;
 
      // one track fit is not kinematic
      if (nTrk == 1) {
        analysis::RaveVertexFitter rsg;
        for (auto& itrack : tracksVertex) {
          rsg.addTrack(itrack);
          nvert = rsg.fit("kalman");
          if (nvert > 0) {
            pos = rsg.getPos(0);
            RerrMatrix = rsg.getCov(0);
            double prob = rsg.getPValue(0);
            ROOT::Math::PxPyPzEVector mom(mother->get4Vector());
            TMatrixDSym errMatrix(7);
            for (int i = 0; i < 7; i++) {
              for (int j = 0; j < 7; j++) {
                if (i > 3 && j > 3) {errMatrix[i][j] = RerrMatrix[i - 4][j - 4];}
                else {errMatrix[i][j] = 0;}
              }
            }
            if (mothIPfit) {
              mother->writeExtraInfo("prodVertX", pos.X());
              mother->writeExtraInfo("prodVertY", pos.Y());
              mother->writeExtraInfo("prodVertZ", pos.Z());
              mother->writeExtraInfo("prodVertSxx", RerrMatrix[0][0]);
              mother->writeExtraInfo("prodVertSxy", RerrMatrix[0][1]);
              mother->writeExtraInfo("prodVertSxz", RerrMatrix[0][2]);
              mother->writeExtraInfo("prodVertSyx", RerrMatrix[1][0]);
              mother->writeExtraInfo("prodVertSyy", RerrMatrix[1][1]);
              mother->writeExtraInfo("prodVertSyz", RerrMatrix[1][2]);
              mother->writeExtraInfo("prodVertSzx", RerrMatrix[2][0]);
              mother->writeExtraInfo("prodVertSzy", RerrMatrix[2][1]);
              mother->writeExtraInfo("prodVertSzz", RerrMatrix[2][2]);
            } else {
              mother->updateMomentum(mom, pos, errMatrix, prob);
            }
            return true;
          } else {return false;}
        }
      } else {
        nvert = rsf.fit();
      }
 
      if (nvert > 0) {
        pos = rsf.getPos();
        RerrMatrix = rsf.getVertexErrorMatrix();
        double prob = rsf.getPValue();
        ROOT::Math::PxPyPzEVector mom(mother->get4Vector());
        TMatrixDSym errMatrix(7);
        for (int i = 0; i < 7; i++) {
          for (int j = 0; j < 7; j++) {
            if (i > 3 && j > 3) {errMatrix[i][j] = RerrMatrix[i - 4][j - 4];}
            else {errMatrix[i][j] = 0;}
          }
        }
        mother->updateMomentum(mom, pos, errMatrix, prob);
      } else {return false;}
 
 
      if (mothSel && nTrk > 1) {
        analysis::RaveSetup::getInstance()->setBeamSpot(pos, RerrMatrix);
        rf.addMother(mother);
        int nKfit = rf.fit();
        rf.updateMother();
        analysis::RaveSetup::getInstance()->unsetBeamSpot();
 
        if (nKfit > 0) {return true;}
        else return false;
      } else return true;
    }
  }
 
  bool okFT = false;
  if (m_fitType == "vertex") {
    okFT = true;
    int nVert = rf.fit();
    rf.updateMother();
    if (m_decayString.empty() && m_updateDaughters == true) rf.updateDaughters();
    if (nVert != 1) return false;
  }
  if (m_fitType == "mass") {
    // add protection
    okFT = true;
    rf.setMassConstFit(true);
    rf.setVertFit(false);
    int nVert = rf.fit();
    rf.updateMother();
    if (nVert != 1) return false;
  };
  if (m_fitType == "massvertex") {
    okFT = true;
    rf.setMassConstFit(true);
    int nVert = rf.fit();
    rf.updateMother();
    if (m_decayString.empty() && m_updateDaughters == true) rf.updateDaughters();
    if (nVert != 1) return false;
  };
  if (!okFT) {
    B2FATAL("fitType : " << m_fitType << " ***invalid fit type ");
  }
 
  return true;
}
 
bool ParticleVertexFitterModule::allSelectedDaughters(const Particle* mother,
                                                      const std::vector<const Particle*>& tracksVertex)
{
  bool isAll = false;
  if (mother->getNDaughters() == 0) return false;
 
  int nNotIncluded = mother->getNDaughters();
 
  for (unsigned i = 0; i < mother->getNDaughters(); i++) {
    bool dauOk = false;
    for (auto& vi : tracksVertex) {
      if (vi == mother->getDaughter(i)) {
        nNotIncluded = nNotIncluded - 1;
        dauOk = true;
      }
    }
    if (!dauOk) {
      if (allSelectedDaughters(mother->getDaughter(i), tracksVertex)) nNotIncluded--;
    }
  }
  if (nNotIncluded == 0) isAll = true;
  return isAll;
}
 
bool ParticleVertexFitterModule::addChildofParticletoKFit(analysis::FourCFitKFit& kf, const Particle* particle)
{
  for (unsigned ichild = 0; ichild < particle->getNDaughters(); ichild++) {
    const Particle* child = particle->getDaughter(ichild);
    if (child->getNDaughters() > 0) addChildofParticletoKFit(kf, child);
    else {
      if (child->getPValue() < 0) return false; // error matrix not valid
 
      kf.addParticle(child);
    }
  }
  return true;
}
 
bool ParticleVertexFitterModule::addChildofParticletoMassKFit(analysis::MassFourCFitKFit& kf, const Particle* particle,
    std::vector<unsigned>& particleId)
{
  for (unsigned ichild = 0; ichild < particle->getNDaughters(); ichild++) {
    const Particle* child = particle->getDaughter(ichild);
    if (child->getNDaughters() > 0) {
      bool massconstraint = std::find(m_massConstraintList.begin(), m_massConstraintList.end(),
                                      std::abs(child->getPDGCode())) != m_massConstraintList.end();
      std::vector<unsigned> childId;
      addChildofParticletoMassKFit(kf, child, childId);
      if (massconstraint) kf.addMassConstraint(child->getPDGMass(), childId);
      particleId.insert(particleId.end(), childId.begin(), childId.end());
    } else {
      if (child->getPValue() < 0) return false; // error matrix not valid
      kf.addParticle(child);
      particleId.push_back(kf.getTrackCount() - 1);
    }
  }
  return true;
}
 
void ParticleVertexFitterModule::addIPProfileToKFit(analysis::VertexFitKFit& kv)
{
  HepPoint3D pos = ROOTToCLHEP::getPoint3D(m_BeamSpotCenter);
  CLHEP::HepSymMatrix covMatrix = ROOTToCLHEP::getHepSymMatrix(m_beamSpotCov);
 
  kv.setIpProfile(pos, covMatrix);
}
 
void ParticleVertexFitterModule::addIPTubeToKFit(analysis::VertexFitKFit& kv)
{
  CLHEP::HepSymMatrix err(7, 0);
 
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      err[i + 4][j + 4] = m_beamSpotCov(i, j);
    }
  }
 
  PCmsLabTransform T;
  ROOT::Math::PxPyPzEVector iptube_mom = T.getBeamFourMomentum();
 
  kv.setIpTubeProfile(
    ROOTToCLHEP::getHepLorentzVector(iptube_mom),
    ROOTToCLHEP::getPoint3D(m_BeamSpotCenter),
    err,
    0.);
}
 
void ParticleVertexFitterModule::findConstraintBoost(double cut)
{
  PCmsLabTransform T;
 
  ROOT::Math::XYZVector boostDir = T.getBoostVector().Unit();
 
  TMatrixDSym beamSpotCov = m_beamSpotDB->getCovVertex();
  beamSpotCov(2, 2) = cut * cut;
  double thetab = boostDir.Theta();
  double phib = boostDir.Phi();
 
  double stb = TMath::Sin(thetab);
  double ctb = TMath::Cos(thetab);
  double spb = TMath::Sin(phib);
  double cpb = TMath::Cos(phib);
 
 
  TMatrix rz(3, 3);  rz(2, 2) = 1;
  rz(0, 0) = cpb; rz(0, 1) = spb;
  rz(1, 0) = -1 * spb; rz(1, 1) = cpb;
 
  TMatrix ry(3, 3);  ry(1, 1) = 1;
  ry(0, 0) = ctb; ry(0, 2) = -1 * stb;
  ry(2, 0) = stb; ry(2, 2) = ctb;
 
  TMatrix r(3, 3);  r.Mult(rz, ry);
  TMatrix rt(3, 3); rt.Transpose(r);
 
  TMatrix TubePart(3, 3);  TubePart.Mult(rt, beamSpotCov);
  TMatrix Tube(3, 3); Tube.Mult(TubePart, r);
 
  m_beamSpotCov(0, 0) = Tube(0, 0);  m_beamSpotCov(0, 1) = Tube(0, 1);  m_beamSpotCov(0, 2) = Tube(0, 2);
  m_beamSpotCov(1, 0) = Tube(1, 0);  m_beamSpotCov(1, 1) = Tube(1, 1);  m_beamSpotCov(1, 2) = Tube(1, 2);
  m_beamSpotCov(2, 0) = Tube(2, 0);  m_beamSpotCov(2, 1) = Tube(2, 1);  m_beamSpotCov(2, 2) = Tube(2, 2);
}
 
void ParticleVertexFitterModule::smearBeamSpot(double width)
{
  TMatrixDSym beamSpotCov = m_beamSpotDB->getCovVertex();
  for (int i = 0; i < 3; i++)
    beamSpotCov(i, i) += width * width;
 
  m_beamSpotCov = beamSpotCov;
}
 
double ParticleVertexFitterModule::getChi2TracksLBoost(const analysis::VertexFitKFit& kv)
{
  double chi2TrackL = 0;
 
  for (int iTrack = 0; iTrack < kv.getTrackCount(); iTrack++) {
 
    analysis::KFitTrack trk_i = kv.getTrack(iTrack); // KFitTrack contains parameters before/after fit.
 
    TMatrixFSym err = CLHEPToROOT::getTMatrixFSym(trk_i.getError(analysis::KFitConst::kBeforeFit)); // px, py, pz, E, x, y, z
 
    ROOT::Math::XYZVector x_before = CLHEPToROOT::getXYZVector(trk_i.getPosition(analysis::KFitConst::kBeforeFit));
    ROOT::Math::XYZVector x_after = CLHEPToROOT::getXYZVector(trk_i.getPosition());
    ROOT::Math::XYZVector dPos = x_after - x_before;
 
    PCmsLabTransform T;
    ROOT::Math::XYZVector boost3 = T.getBoostVector().Unit();
    TVectorD boostD(0, 6, 0., 0., 0., 0., boost3.X(), boost3.Y(), boost3.Z(), "END");
 
    double dLBoost = dPos.Dot(boost3);
 
    chi2TrackL += TMath::Power(dLBoost, 2) / err.Similarity(boostD);
  }
  return chi2TrackL;
}