BtubeCreatorModule.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.                  *
 **************************************************************************/
 
#include <analysis/modules/BtubeCreator/BtubeCreatorModule.h>
 
// framework aux
#include <framework/gearbox/Unit.h>
#include <framework/gearbox/Const.h>
#include <framework/logging/Logger.h>
 
// dataobjects
#include <analysis/dataobjects/Particle.h>
#include <analysis/DecayDescriptor/ParticleListName.h>
 
// utilities
#include <analysis/utility/PCmsLabTransform.h>
#include <analysis/utility/ParticleCopy.h>
 
// Magnetic field
#include <framework/geometry/BFieldManager.h>
 
#include <TMath.h>
#include <Eigen/Core>
 
using namespace std;
using namespace Belle2;
 
//-----------------------------------------------------------------
//                 Register the Module
//-----------------------------------------------------------------
REG_MODULE(BtubeCreator)
 
//-----------------------------------------------------------------
//                 Implementation
//-----------------------------------------------------------------
 
BtubeCreatorModule::BtubeCreatorModule() : Module(),
  m_Bfield(0)
{
  // Set module properties
  setDescription("BtubeCreator : This module creates Btube object, an object geometrically similar to a very long ellipsoid along a particular direction and can be used as a constraint in vertexing B particles. Upsilon4S decays to two Bs. the user selects one B with a ^ in decaystring. The order of daughters in reconstructdecay of Upsilon4S and this decaystring should be same. Using selected B as reference, the module calculates the direction in which the other B should fly and constructs a Btube object along that direction. In semi-leptonic analyses, the selected B is usually the fully reconstructed one, while for time dependent studies, the selected B is usually signal B which can be partially reconstructed");
 
  // Parameter definitions
  addParam("listName", m_listName, "name of mother particle list", string(""));
  addParam("confidenceLevel", m_confidenceLevel, "Confidence level to accept the fit.", 0.001);
  addParam("decayString", m_decayString,
           "decay string of the mother particle, the selected daughter specifies which daughter will be used as reference to create Btube",
           string(""));
  addParam("associateBtubeToBselected", m_associateBtubeToBselected,
           "whether to associate the Btube with the selected B",
           false);
  addParam("verbosity", m_verbose, "print statements", true);
}
 
void BtubeCreatorModule::initialize()
{
 
  m_plist.isRequired(m_listName);
 
  // magnetic field
  m_Bfield = BFieldManager::getField(TVector3(0, 0, 0)).Z() / Unit::T;
 
  m_BeamSpotCenter = m_beamSpotDB->getIPPosition();
  m_beamSpotCov.ResizeTo(3, 3);
  m_beamSpotCov = m_beamSpotDB->getCovVertex();
  B2INFO("BtubeCreator : magnetic field = " << m_Bfield);
 
  m_tubeArray.registerInDataStore();
  StoreArray<Particle>().registerRelationTo(m_tubeArray);
 
  bool valid = m_decaydescriptor.init(m_decayString);
  if (!valid)
    B2ERROR("BtubeCreatorModule: invalid decay string" << m_decayString);
  int nProducts = m_decaydescriptor.getNDaughters();
  if (nProducts != 2)
    B2ERROR("BtubeCreatorModule: decay string should contain only two daughters");
}
 
void BtubeCreatorModule::event()
{
  analysis::RaveSetup::initialize(1, m_Bfield);
 
  std::vector<unsigned int> toRemove;
  unsigned int n = m_plist->getListSize();
 
  for (unsigned i = 0; i < n; i++) {
    Particle* particle = m_plist->getParticle(i);
 
    std::vector<Particle*> daughtervec = particle->getDaughters();
    std::vector<const Particle*> selParticles = m_decaydescriptor.getSelectionParticles(particle);
    if (selParticles.size() > 1) {
      B2FATAL("Please select only one daughter which will be used as reference to create Btube");
    }
 
    int selectindex = 1;
    if ((daughtervec.at(0))->getArrayIndex() == (selParticles.at(0))->getArrayIndex()) selectindex = 0 ;
 
    Particle* tubecreatorB = const_cast<Particle*>(particle->getDaughter(selectindex));
    Particle* otherB = const_cast<Particle*>(particle->getDaughter(1 - selectindex));
 
    if ((tubecreatorB->getVertexErrorMatrix()(2, 2)) == 0.0) {
      B2FATAL("Please perform a vertex fit of the selected B before calling this module");
    }
 
    //make a copy of tubecreatorB so as not to modify the original object
 
    Particle* tubecreatorBCopy = ParticleCopy::copyParticle(tubecreatorB);
 
    if (m_verbose) {
      B2DEBUG(10, "tubecreator  B decay vertex: ");
      B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << tubecreatorBCopy->getVertex()[0] << "," << std::fixed <<
              std::setprecision(
                20) << tubecreatorBCopy->getVertex()[1] << "," << std::fixed << std::setprecision(20) << tubecreatorBCopy->getVertex()[2] << "}");
    }
 
    bool ok0 = doVertexFit(tubecreatorBCopy);
 
    if (ok0) {
      if (tubecreatorBCopy->getPValue() < m_confidenceLevel) {
        toRemove.push_back(particle->getArrayIndex());
      } else {
        particle->setVertex(tubecreatorBCopy->getVertex());
        particle->setMomentumVertexErrorMatrix(tubecreatorBCopy->getMomentumVertexErrorMatrix());
 
        tubecreatorB->writeExtraInfo("prod_vtx_x", tubecreatorBCopy->getVertex()[0]);
        tubecreatorB->writeExtraInfo("prod_vtx_y", tubecreatorBCopy->getVertex()[1]);
        tubecreatorB->writeExtraInfo("prod_vtx_z", tubecreatorBCopy->getVertex()[2]);
        tubecreatorB->writeExtraInfo("prod_vtx_cov00", tubecreatorBCopy->getVertexErrorMatrix()(0, 0));
        tubecreatorB->writeExtraInfo("prod_vtx_cov01", tubecreatorBCopy->getVertexErrorMatrix()(0, 1));
        tubecreatorB->writeExtraInfo("prod_vtx_cov02", tubecreatorBCopy->getVertexErrorMatrix()(0, 2));
        tubecreatorB->writeExtraInfo("prod_vtx_cov10", tubecreatorBCopy->getVertexErrorMatrix()(1, 0));
        tubecreatorB->writeExtraInfo("prod_vtx_cov11", tubecreatorBCopy->getVertexErrorMatrix()(1, 1));
        tubecreatorB->writeExtraInfo("prod_vtx_cov12", tubecreatorBCopy->getVertexErrorMatrix()(1, 2));
        tubecreatorB->writeExtraInfo("prod_vtx_cov20", tubecreatorBCopy->getVertexErrorMatrix()(2, 0));
        tubecreatorB->writeExtraInfo("prod_vtx_cov21", tubecreatorBCopy->getVertexErrorMatrix()(2, 1));
        tubecreatorB->writeExtraInfo("prod_vtx_cov22", tubecreatorBCopy->getVertexErrorMatrix()(2, 2));
 
        tubecreatorB->writeExtraInfo("Px_after_avf", (tubecreatorBCopy->get4Vector()).Px());
        tubecreatorB->writeExtraInfo("Py_after_avf", (tubecreatorBCopy->get4Vector()).Py());
        tubecreatorB->writeExtraInfo("Pz_after_avf", (tubecreatorBCopy->get4Vector()).Pz());
        tubecreatorB->writeExtraInfo("E_after_avf", (tubecreatorBCopy->get4Vector()).E());
 
        Eigen::Matrix<double, 3, 1> tubecreatorBOriginpos(tubecreatorBCopy->getVertex()[0], tubecreatorBCopy->getVertex()[1],
                                                          tubecreatorBCopy->getVertex()[2]);
        TLorentzVector v4Final = tubecreatorBCopy->get4Vector();
        PCmsLabTransform T;
        TLorentzVector vec = T.rotateLabToCms() * v4Final;
        TLorentzVector vecNew(-1 * vec.Px(), -1 * vec.Py(), -1 * vec.Pz(), vec.E());
        TLorentzVector v4FinalNew = T.rotateCmsToLab() * vecNew;
 
        if (m_verbose) {
          B2DEBUG(10, "beamspot center :");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << m_BeamSpotCenter.X() << "," << std::fixed << std::setprecision(
                    20) << m_BeamSpotCenter.Y() << "," << std::fixed << std::setprecision(20) << m_BeamSpotCenter.Z() << "}");
          B2DEBUG(10, "beamspot cov :");
 
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) <<  m_beamSpotCov(0,
                  0) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(0,
                      1) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(0, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) <<  m_beamSpotCov(1,
                  0) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(1,
                      1) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(1, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << m_beamSpotCov(2,
                  0) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(2,
                      1) << "," << std::fixed << std::setprecision(20) << m_beamSpotCov(2, 2) << "}");
        }
        TMatrixFSym pp = (tubecreatorBCopy->getMomentumErrorMatrix()).GetSub(0, 2, 0, 2, "S");
        double pe = tubecreatorBCopy->getMomentumErrorMatrix()(2, 2);
        TMatrixFSym pv = tubecreatorBCopy->getVertexErrorMatrix();
 
        // start rotation
 
        double theta = v4FinalNew.Theta();
        double phi = v4FinalNew.Phi();
 
        double st = TMath::Sin(theta);
        double ct = TMath::Cos(theta);
        double sp = TMath::Sin(phi);
        double cp = TMath::Cos(phi);
 
        TMatrix r2z(3, 3);  r2z(2, 2) = 1;
        r2z(0, 0) = cp; r2z(0, 1) = -1 * sp;
        r2z(1, 0) = sp; r2z(1, 1) = cp;
 
        TMatrix r2y(3, 3);  r2y(1, 1) = 1;
        r2y(0, 0) = ct; r2y(0, 2) = st;
        r2y(2, 0) = -1 * st; r2y(2, 2) = ct;
 
        TMatrix r2(3, 3);  r2.Mult(r2z, r2y);
        TMatrix r2t(3, 3); r2t.Transpose(r2);
 
        TMatrix longerror(3, 3); longerror(2, 2) = 1000;
        TMatrix longerror_temp(3, 3); longerror_temp.Mult(r2, longerror);
        TMatrix longerrorRotated(3, 3); longerrorRotated.Mult(longerror_temp, r2t);
 
        TMatrix pvNew(3, 3);
        pvNew += pv;
        pvNew += longerrorRotated;
 
        TMatrixFSym errNew(7);
        errNew.SetSub(0, 0, pp);
        errNew.SetSub(4, 4, pvNew);
        errNew(3, 3) = pe;
 
        TMatrixFSym tubeMat(3);
        tubeMat.SetSub(0, 0, pvNew);
 
        TMatrixFSym tubeMatCenterError(3);
        tubeMatCenterError.SetSub(0, 0, pv);
 
        if (m_verbose) {
          B2DEBUG(10, "B origin error matrix  :  ");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << pv(0, 0) << "," << std::fixed << std::setprecision(20) << pv(0,
                  1) << "," << std::fixed << std::setprecision(20) << pv(0, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << pv(1, 0) << "," << std::fixed << std::setprecision(20) << pv(1,
                  1) << "," << std::fixed << std::setprecision(20) << pv(1, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << pv(2, 0) << "," << std::fixed << std::setprecision(20) << pv(2,
                  1) << "," << std::fixed << std::setprecision(20) << pv(2, 2) << "}");
 
          B2DEBUG(10, "B tube error matrix  :  ");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) <<  pvNew(0, 0) << "," << std::fixed << std::setprecision(20) << pvNew(0,
                  1) << "," << std::fixed << std::setprecision(20) << pvNew(0, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) <<  pvNew(1, 0) << "," << std::fixed << std::setprecision(20) << pvNew(1,
                  1) << "," << std::fixed << std::setprecision(20) << pvNew(1, 2) << "},");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << pvNew(2, 0) << "," << std::fixed << std::setprecision(20) << pvNew(2,
                  1) << "," << std::fixed << std::setprecision(20) << pvNew(2, 2) << "}");
 
          B2DEBUG(10, "B origin  ");
          B2DEBUG(10, "{" << std::fixed << std::setprecision(20) << tubecreatorBCopy->getVertex()[0] << "," << std::fixed <<
                  std::setprecision(
                    20) << tubecreatorBCopy->getVertex()[1] << "," << std::fixed << std::setprecision(20) << tubecreatorBCopy->getVertex()[2] << "}");
        }
 
        tubecreatorBCopy->setMomentumVertexErrorMatrix(errNew);
 
        Btube* tubeconstraint = m_tubeArray.appendNew(Btube());
        if (m_associateBtubeToBselected) {
          tubecreatorB->addRelationTo(tubeconstraint);
        } else {
          otherB->addRelationTo(tubeconstraint);
        }
 
        tubeconstraint->setTubeCenter(tubecreatorBOriginpos);
        tubeconstraint->setTubeMatrix(tubeMat);
        tubeconstraint->setTubeCenterErrorMatrix(tubeMatCenterError);
 
        if (m_associateBtubeToBselected) {
          addextrainfos(tubecreatorB, tubecreatorBCopy, pvNew, v4FinalNew);
        } else {
          addextrainfos(otherB, tubecreatorBCopy, pvNew, v4FinalNew);
        }
      }
    }
    if (!ok0) toRemove.push_back(particle->getArrayIndex());
  }
  m_plist->removeParticles(toRemove);
 
  analysis::RaveSetup::getInstance()->reset();
}
 
bool BtubeCreatorModule::doVertexFit(Particle* mother)
{
  analysis::RaveSetup::getInstance()->setBeamSpot(m_BeamSpotCenter, m_beamSpotCov);
 
  analysis::RaveVertexFitter rsg;
  rsg.addTrack(mother);
  int nvert = rsg.fit("avf");
 
  if (nvert == 1) {
    rsg.updateDaughters();
    double pValue = rsg.getPValue();
    mother->setPValue(pValue);
  } else {return false;}
  return true;
}
 
void BtubeCreatorModule::addextrainfos(Particle* daughter, Particle* copy, TMatrix mat, TLorentzVector TLV)
{
  daughter->writeExtraInfo("TubePosX", copy->getVertex()[0]);
  daughter->writeExtraInfo("TubePosY", copy->getVertex()[1]);
  daughter->writeExtraInfo("TubePosZ", copy->getVertex()[2]);
 
  daughter->writeExtraInfo("TubeCov00", mat(0, 0));
  daughter->writeExtraInfo("TubeCov01", mat(0, 1));
  daughter->writeExtraInfo("TubeCov02", mat(0, 2));
  daughter->writeExtraInfo("TubeCov10", mat(1, 0));
  daughter->writeExtraInfo("TubeCov11", mat(1, 1));
  daughter->writeExtraInfo("TubeCov12", mat(1, 2));
  daughter->writeExtraInfo("TubeCov20", mat(2, 0));
  daughter->writeExtraInfo("TubeCov21", mat(2, 1));
  daughter->writeExtraInfo("TubeCov22", mat(2, 2));
 
  daughter->writeExtraInfo("TubeDirX", (TLV.Px() / TLV.Mag()));
  daughter->writeExtraInfo("TubeDirY", (TLV.Py() / TLV.Mag()));
  daughter->writeExtraInfo("TubeDirZ", (TLV.Pz() / TLV.Mag()));
  daughter->writeExtraInfo("TubeB_p_estimated", TLV.Mag());
}