RecoPhoton Class Reference

representation of the photon constraint More...

#include <RecoPhoton.h>

Inheritance diagram for RecoPhoton:

Collaboration diagram for RecoPhoton:

Public Types
enum	TFParticleType {   kInteractionPoint ,   kOrigin ,   kComposite ,   kRecoResonance ,   kInternalParticle ,   kRecoTrack ,   kResonance ,   kRecoPhoton ,   kRecoKlong ,   kMissingParticle }
	particle types More...
typedef std::vector< Constraint >	constraintlist
	alias
typedef std::vector< std::pair< const ParticleBase *, int > >	indexmap
	alias

Public Member Functions
	RecoPhoton (Belle2::Particle *bc, const ParticleBase *mother)
	constructor
virtual	~RecoPhoton ()
	destructor
virtual ErrCode	initParticleWithMother (FitParams &fitparams) override
	init particle with mother
virtual ErrCode	initMotherlessParticle (FitParams &fitparams) override
	init particle without mother
ErrCode	initCovariance (FitParams &fitparams) const override
	init covariance
ErrCode	initParams ()
	update or init params
ErrCode	projectRecoConstraint (const FitParams &fitparams, Projection &p) const override
	project photon constraint
virtual int	dimM () const override
	sets the size of the corresponding residual projection
virtual bool	hasEnergy () const override
	how should the energy be calculated ? from momentum or from E ?
virtual int	dim () const override
	set the size of the particle in the statevector
virtual int	type () const override
	type
virtual void	addToConstraintList (constraintlist &alist, int depth) const override
	add to list
virtual std::string	parname (int index) const override
	name
virtual int	momIndex () const override
	get momentum index
virtual ErrCode	projectConstraint (Constraint::Type, const FitParams &, Projection &) const override
	abstract abstract projection
virtual void	updateIndex (int &offset)
	this sets the index for momentum, position, etc.
const ParticleBase *	locate (Belle2::Particle *particle) const
	get particle base from basf2 particle
Belle2::Particle *	particle () const
	get basf2 particle
int	index () const
	get index
const ParticleBase *	mother () const
	getMother() / hasMother()
virtual ErrCode	projectGeoConstraint (const FitParams &, Projection &) const
	project geometrical constraint
virtual ErrCode	projectMassConstraintParticle (const FitParams &, Projection &) const
	project mass constraint using the particles parameters
virtual ErrCode	projectMassConstraintDaughters (const FitParams &, Projection &) const
	project mass constraint using the parameters of the daughters
virtual ErrCode	projectMassConstraint (const FitParams &, Projection &) const
	project mass constraint abstract
virtual void	forceP4Sum (FitParams &) const
	force p4 sum conservation all along the tree
virtual int	posIndex () const
	get vertex index (in statevector!)
virtual int	tauIndex () const
	get tau index
virtual bool	hasPosition () const
	get false
int	eneIndex () const
	get energy index
virtual double	chiSquare (const FitParams &) const
	get chi2
int	charge () const
	get charge
virtual ParticleBase *	addDaughter (Belle2::Particle *, const ConstraintConfiguration &config, bool forceFitAll=false)
	add daughter
virtual void	removeDaughter (const ParticleBase *pb)
	remove daughter
virtual void	retrieveIndexMap (indexmap &anindexmap) const
	get index map
void	setMother (const ParticleBase *m)
	set mother
void	collectVertexDaughters (std::vector< ParticleBase * > &particles, int posindex)
	get vertex daughters
virtual int	nFinalChargedCandidates () const
	number of charged candidates

Static Public Member Functions
static bool	useEnergy (const Belle2::Particle &cand)
	has energy in fit params?
static ParticleBase *	createParticle (Belle2::Particle *particle, const ParticleBase *mother, const ConstraintConfiguration &config, bool forceFitAll=false)
	create the according treeFitter particle obj for a basf2 particle type
static ParticleBase *	createOrigin (Belle2::Particle *daughter, const ConstraintConfiguration &config, bool forceFitAll)
	create a custom origin particle or a beamspot

Protected Types
typedef std::vector< ParticleBase * >	ParticleContainer
	just an alias

Protected Member Functions
ErrCode	initTau (FitParams &par) const
	initialises tau as a length
void	setIndex (int i)
	set Index (in statevector)

Static Protected Member Functions
static bool	isAResonance (Belle2::Particle *particle)
	controls if a particle is treated as a resonance(lifetime=0) or a particle that has a finite lifetime.

Protected Attributes
Belle2::Particle *	m_particle
	pointer to framework type
const ParticleBase *	m_mother
	motherparticle
std::vector< ParticleBase * >	m_daughters
	daughter container
bool	m_isStronglyDecayingResonance
	decay length less than 1 micron
const ConstraintConfiguration *	m_config
	has all the constraint config

Private Attributes
const int	m_dim
	dimension of residuals and 'width' of H
bool	m_init
	was initialized*
bool	m_useEnergy
	has energy ins statevector
Eigen::Matrix< double, 1, 4 >	m_clusterPars
	constrains measured params (x_c, y_c, z_c, E_c)
Eigen::Matrix< double, 4, 4 >	m_covariance
	covariance (x_c,y_c,z_c,E_c) of measured pars
int	m_i1
	index with the highest momentum.
int	m_i2
	random other index
int	m_i3
	another random index
const float	m_momentumScalingFactor
	scale the momentum / energy by this correction factor
int	m_index
	index
std::string	m_name
	name

Detailed Description

representation of the photon constraint

Definition at line 16 of file RecoPhoton.h.

Member Typedef Documentation

constraintlist

typedef std::vector<Constraint> constraintlist

inherited

alias

Definition at line 52 of file ParticleBase.h.

indexmap

typedef std::vector< std::pair<const ParticleBase*, int> > indexmap

inherited

alias

Definition at line 55 of file ParticleBase.h.

ParticleContainer

typedef std::vector<ParticleBase*> ParticleContainer

protectedinherited

just an alias

Definition at line 178 of file ParticleBase.h.

Member Enumeration Documentation

TFParticleType

enum TFParticleType

inherited

particle types

Definition at line 30 of file ParticleBase.h.

                        {kInteractionPoint,
                         kOrigin,
                         kComposite,
                         kRecoResonance,
                         kInternalParticle,
                         kRecoTrack,
                         kResonance,
                         kRecoPhoton,
                         kRecoKlong,
                         kMissingParticle
                        };

Constructor & Destructor Documentation

RecoPhoton()

RecoPhoton	(	Belle2::Particle *	bc,
		const ParticleBase *	mother
	)

constructor

Definition at line 26 of file RecoPhoton.cc.

                                                                             : RecoParticle(particle, mother),
    m_dim(3),
    m_init(false),
    m_useEnergy(useEnergy(*particle)),
    m_clusterPars(),
    m_covariance(),
    m_momentumScalingFactor(particle->getEffectiveMomentumScale())
  {
    initParams();
  }

~RecoPhoton()

virtual ~RecoPhoton ( )

inlinevirtual

destructor

Definition at line 23 of file RecoPhoton.h.

{};

Member Function Documentation

addDaughter()

ParticleBase * addDaughter ( Belle2::Particle *  cand, const ConstraintConfiguration &  config, bool  forceFitAll = false  )

virtualinherited

add daughter

Definition at line 65 of file ParticleBase.cc.

  {
    auto newDaughter = ParticleBase::createParticle(cand, this, config, forceFitAll);
    m_daughters.push_back(newDaughter);
    return m_daughters.back();
  }

addToConstraintList()

virtual void addToConstraintList ( constraintlist &  alist, int  depth  ) const

inlineoverridevirtual

add to list

Implements ParticleBase.

Definition at line 53 of file RecoPhoton.h.

    {
      alist.push_back(Constraint(this, Constraint::photon, depth, dimM())) ;
    }

charge()

int charge ( ) const

inlineinherited

get charge

Definition at line 144 of file ParticleBase.h.

    {
      if (m_particle->getPDGCode()) {
        double fltcharge = m_particle->getCharge();
        return fltcharge < 0 ? int(fltcharge - 0.5) : int(fltcharge + 0.5);
      } else {
        return m_particle->getCharge() > 0 ? 1 : (m_particle->getCharge() < 0 ? -1 : 0);
      }
    }

chiSquare()

double chiSquare ( const FitParams &  fitparams ) const

virtualinherited

get chi2

Definition at line 231 of file ParticleBase.cc.

  {
    double rc = 0;
    for (auto* daughter : m_daughters) {
      rc += daughter->chiSquare(fitparams);
    }
    return rc;
  }

collectVertexDaughters()

void collectVertexDaughters ( std::vector< ParticleBase * > &  particles, int  posindex  )

inherited

get vertex daughters

Definition at line 156 of file ParticleBase.cc.

  {
    if (mother() && mother()->posIndex() == posindex) {
      particles.push_back(this);
    }
 
    for (auto* daughter : m_daughters) {
      daughter->collectVertexDaughters(particles, posindex);
    }
  }

createOrigin()

ParticleBase * createOrigin ( Belle2::Particle *  daughter, const ConstraintConfiguration &  config, bool  forceFitAll  )

staticinherited

create a custom origin particle or a beamspot

Definition at line 93 of file ParticleBase.cc.

  {
    return new Origin(daughter, config, forceFitAll);
  }

createParticle()

ParticleBase * createParticle ( Belle2::Particle *  particle, const ParticleBase *  mother, const ConstraintConfiguration &  config, bool  forceFitAll = false  )

staticinherited

create the according treeFitter particle obj for a basf2 particle type

Definition at line 102 of file ParticleBase.cc.

  {
    ParticleBase* rc = nullptr;
 
    if (!mother) { // If there is no mother, this is the 'head of tree' particle (is never a resonance)
      rc = new InternalParticle(particle, nullptr, config, forceFitAll);
    } else if (particle->hasExtraInfo("bremsCorrected") // Has Bremsstrahlungs-recovery
               && particle->getExtraInfo("bremsCorrected") != 0) { // and gammas are attached
      rc = new Composite(particle, mother, config, true);
      // if no gamma is attached, it is treated as a RecoTrack
    } else if (particle->hasExtraInfo("treeFitterTreatMeAsInvisible")
               && particle->getExtraInfo("treeFitterTreatMeAsInvisible") == 1) { // dummy particles with invisible flag
      rc = new RecoResonance(particle, mother, config);
    } else if (particle->getTrack()) { // external reconstructed track
      rc = new RecoTrack(particle, mother);
    } else if (particle->getECLCluster()) { // external reconstructed photon
      rc = new RecoPhoton(particle, mother);
    } else if (particle->getKLMCluster()) { // external reconstructed klong
      rc = new RecoKlong(particle, mother);
    } else if (particle->getMdstArrayIndex()) { // external composite e.g. V0
      rc = new InternalParticle(particle, mother, config, forceFitAll);
    } else { // 'internal' particles
      if (isAResonance(particle)) {
        rc = new Resonance(particle, mother, config, forceFitAll);
      } else {
        rc = new InternalParticle(particle, mother, config, forceFitAll);
      }
    }
    return rc;
  }

dim()

virtual int dim ( ) const

inlineoverridevirtual

set the size of the particle in the statevector

Reimplemented from RecoParticle.

Definition at line 47 of file RecoPhoton.h.

{ return m_dim; }

dimM()

virtual int dimM ( ) const

inlineoverridevirtual

sets the size of the corresponding residual projection

Implements RecoParticle.

Definition at line 41 of file RecoPhoton.h.

{ return dim(); }

eneIndex()

int eneIndex ( ) const

inlineinherited

get energy index

Definition at line 138 of file ParticleBase.h.

{ return hasEnergy() ? momIndex() + 3 : -1 ; }

forceP4Sum()

virtual void forceP4Sum ( FitParams &  ) const

inlinevirtualinherited

force p4 sum conservation all along the tree

Reimplemented in InternalParticle.

Definition at line 116 of file ParticleBase.h.

{} ;

hasEnergy()

virtual bool hasEnergy ( ) const

inlineoverridevirtual

how should the energy be calculated ? from momentum or from E ?

Reimplemented from RecoParticle.

Definition at line 44 of file RecoPhoton.h.

{ return false; }

hasPosition()

virtual bool hasPosition ( ) const

inlinevirtualinherited

get false

Reimplemented in Composite, InternalParticle, and Resonance.

Definition at line 135 of file ParticleBase.h.

{ return false ; }

index()

int index ( ) const

inlineinherited

get index

Definition at line 95 of file ParticleBase.h.

{ return m_index ; }

initCovariance()

ErrCode initCovariance ( FitParams &  fitparams ) const

overridevirtual

init covariance

Reimplemented from ParticleBase.

Definition at line 75 of file RecoPhoton.cc.

  {
    const int momindex = momIndex();
    const int posindex = mother()->posIndex();
 
    const double factorE = 1000 * m_covariance(3, 3);
    const double factorX = 1000; // ~ 10cm error on initial vertex
 
    fitparams.getCovariance().block<4, 4>(momindex, momindex) =
      Eigen::Matrix<double, 4, 4>::Identity(4, 4) * factorE;
 
    fitparams.getCovariance().block<3, 3>(posindex, posindex) =
      Eigen::Matrix<double, 3, 3>::Identity(3, 3) * factorX;
 
    return ErrCode(ErrCode::Status::success);
  }

initMotherlessParticle()

ErrCode initMotherlessParticle ( FitParams &  fitparams )

overridevirtual

init particle without mother

Reimplemented from RecoParticle.

Definition at line 58 of file RecoPhoton.cc.

  {
    return ErrCode(ErrCode::Status::success);
  }

initParams()

ErrCode initParams

(

)

update or init params

Definition at line 92 of file RecoPhoton.cc.

  {
    const Belle2::ECLCluster* cluster = particle()->getECLCluster();
    const Belle2::ECLCluster::EHypothesisBit clusterhypo = particle()->getECLClusterEHypothesisBit();
    const Belle2::B2Vector3D centroid = cluster->getClusterPosition();
    const double energy = cluster->getEnergy(clusterhypo);
 
    m_init = true;
    m_covariance = Eigen::Matrix<double, 4, 4>::Zero(4, 4);
    Belle2::ClusterUtils C;
 
    TMatrixDSym cov_EPhiTheta = C.GetCovarianceMatrix3x3FromCluster(cluster);
 
    Eigen::Matrix<double, 2, 2> covPhiTheta = Eigen::Matrix<double, 2, 2>::Zero(2, 2);
 
    for (int row = 0; row < 2; ++row) {
      // we go through all elements here instead of selfadjoint view later
      for (int col = 0; col < 2; ++col) {
        covPhiTheta(row, col) = cov_EPhiTheta[row + 1][col + 1];
      }
    }
 
    // the in going x-E correlations are 0 so we don't fill them
    const double R = cluster->getR();
    const double theta = cluster->getPhi();
    const double phi = cluster->getTheta();
 
    const double st = std::sin(theta);
    const double ct = std::cos(theta);
    const double sp = std::sin(phi);
    const double cp = std::cos(phi);
 
    Eigen::Matrix<double, 2, 3> polarToCartesian = Eigen::Matrix<double, 2, 3>::Zero(2, 3);
 
    // polarToCartesian({phi,theta} -> {x,y,z} )
    polarToCartesian(0, 0) = -1. * R * st * sp; // dx/dphi
    polarToCartesian(0, 1) = R * st * cp;       // dy/dphi
    polarToCartesian(0, 2) = 0;                 // dz/dphi
 
    polarToCartesian(1, 0) = R * ct * cp;  // dx/dtheta
    polarToCartesian(1, 1) = R * ct * sp;  // dy/dtheta
    polarToCartesian(1, 2) = -1. * R * st; // dz/dtheta
 
    m_covariance.block<3, 3>(0, 0) = polarToCartesian.transpose() * covPhiTheta * polarToCartesian;
 
    m_covariance(3, 3) = cov_EPhiTheta[0][0];
    m_clusterPars(0) = centroid.X();
    m_clusterPars(1) = centroid.Y();
    m_clusterPars(2) = centroid.Z();
    m_clusterPars(3) = energy;
 
    auto p_vec = particle()->getMomentum();
    // find highest momentum, eliminate dim with highest mom
    if ((std::abs(p_vec.X()) >= std::abs(p_vec.Y())) && (std::abs(p_vec.X()) >= std::abs(p_vec.Z()))) {
      m_i1 = 0;
      m_i2 = 1;
      m_i3 = 2;
    } else if ((std::abs(p_vec.Y()) >= std::abs(p_vec.X())) && (std::abs(p_vec.Y()) >= std::abs(p_vec.Z()))) {
      m_i1 = 1;
      m_i2 = 0;
      m_i3 = 2;
    } else if ((std::abs(p_vec.Z()) >= std::abs(p_vec.Y())) && (std::abs(p_vec.Z()) >= std::abs(p_vec.X()))) {
      m_i1 = 2;
      m_i2 = 1;
      m_i3 = 0;
    } else {
      B2ERROR("Could not estimate highest momentum for photon constraint. Aborting this fit.\n px: "
              << p_vec.X() << " py: " << p_vec.Y() << " pz: " << p_vec.Z() << " calculated from Ec: " << m_clusterPars(3));
      return ErrCode(ErrCode::Status::photondimerror);
    }
 
    return ErrCode(ErrCode::Status::success);
  }

initParticleWithMother()

ErrCode initParticleWithMother ( FitParams &  fitparams )

overridevirtual

init particle with mother

Implements ParticleBase.

Definition at line 37 of file RecoPhoton.cc.

  {
    const int posindexmother = mother()->posIndex();
 
    Eigen::Matrix<double, 1, 3> vertexToCluster = Eigen::Matrix<double, 1, 3>::Zero(1, 3);
    for (unsigned int i = 0; i < 3; ++i) {
      vertexToCluster(i) = m_clusterPars(i) - fitparams.getStateVector()(posindexmother + i);
    }
 
    const double distanceToMother = vertexToCluster.norm();
    const double energy = m_momentumScalingFactor * m_clusterPars(3); // apply scaling factor to correct energy bias
    const int momindex = momIndex();
 
    for (unsigned int i = 0; i < 3; ++i) {
      // px = E dx/|dx|
      fitparams.getStateVector()(momindex + i) = energy * vertexToCluster(i) / distanceToMother;
    }
 
    return ErrCode(ErrCode::Status::success);
  }

initTau()

ErrCode initTau ( FitParams &  par ) const

protectedinherited

initialises tau as a length

Definition at line 426 of file ParticleBase.cc.

  {
    const int tauindex = tauIndex();
    if (tauindex >= 0 && hasPosition()) {
 
      const int posindex = posIndex();
      const int mother_ps_index = mother()->posIndex();
      const int dim  = m_config->m_originDimension; // TODO can we configure this to be particle specific?
 
      // tau has different meaning depending on the dimension of the constraint
      // 2-> use x-y projection
      const Eigen::Matrix < double, 1, -1, 1, 1, 3 > vertex_dist =
        fitparams.getStateVector().segment(posindex, dim) - fitparams.getStateVector().segment(mother_ps_index, dim);
      const Eigen::Matrix < double, 1, -1, 1, 1, 3 >
      mom = fitparams.getStateVector().segment(posindex, dim) - fitparams.getStateVector().segment(mother_ps_index, dim);
 
      // if an intermediate vertex is not well defined by a track or so it will be initialised with 0
      // same for the momentum of for example B0, it might be initialised with 0
      // in those cases use pdg value
      const double mom_norm = mom.norm();
      const double dot = std::abs(vertex_dist.dot(mom));
      const double tau = dot / mom_norm;
      if (0 == mom_norm || 0 == dot) {
        const double mass = m_particle->getPDGMass();
        if (mass > 0)
          fitparams.getStateVector()(tauindex) = m_particle->getPDGLifetime() * 1e9 * Belle2::Const::speedOfLight / mass;
        else
          fitparams.getStateVector()(tauindex) = 0;
      } else {
        fitparams.getStateVector()(tauindex) = tau;
      }
    }
 
    return ErrCode(ErrCode::Status::success);
  }

isAResonance()

bool isAResonance ( Belle2::Particle *  particle )

staticprotectedinherited

controls if a particle is treated as a resonance(lifetime=0) or a particle that has a finite lifetime.

A finite life time means it will register a geo constraint for this particle

Definition at line 134 of file ParticleBase.cc.

  {
    bool rc = false ;
    const int pdgcode = std::abs(particle->getPDGCode());
 
    if (pdgcode && !(particle->getMdstArrayIndex())) {
      switch (pdgcode) {
        case 22:  //photon conversion
          rc = false;
          break ;
 
        case -11: //bremsstrahlung
        case 11:
          rc = true ;
          break ;
        default: //everything with boosted flight length less than 1 micrometer
          rc = (pdgcode && particle->getPDGLifetime() < 1e-14);
      }
    }
    return rc ;
  }

locate()

const ParticleBase * locate ( Belle2::Particle *  particle ) const

inherited

get particle base from basf2 particle

Definition at line 211 of file ParticleBase.cc.

  {
    const ParticleBase* rc = (m_particle == particle) ? this : nullptr;
    if (!rc) {
      for (auto* daughter : m_daughters) {
        rc = daughter->locate(particle);
        if (rc) {break;}
      }
    }
    return rc;
  }

momIndex()

virtual int momIndex ( ) const

inlineoverridevirtualinherited

get momentum index

Reimplemented from ParticleBase.

Definition at line 42 of file RecoParticle.h.

{ return index(); }

mother()

const ParticleBase * mother ( ) const

inlineinherited

getMother() / hasMother()

Definition at line 98 of file ParticleBase.h.

{ return m_mother; };

nFinalChargedCandidates()

int nFinalChargedCandidates ( ) const

virtualinherited

number of charged candidates

Reimplemented in RecoTrack.

Definition at line 240 of file ParticleBase.cc.

  {
    int rc = 0;
    for (auto* daughter : m_daughters) {
      rc += daughter->nFinalChargedCandidates();
    }
    return rc;
  }

parname()

std::string parname ( int  index ) const

overridevirtualinherited

name

Reimplemented from ParticleBase.

Definition at line 23 of file RecoParticle.cc.

  {
    return ParticleBase::parname(index + 4);
  }

particle()

Belle2::Particle * particle ( ) const

inlineinherited

get basf2 particle

Definition at line 92 of file ParticleBase.h.

{ return m_particle ; }

posIndex()

virtual int posIndex ( ) const

inlinevirtualinherited

get vertex index (in statevector!)

Reimplemented in Composite, InternalParticle, Origin, RecoResonance, and Resonance.

Definition at line 122 of file ParticleBase.h.

{ return -1 ; }

projectConstraint()

ErrCode projectConstraint ( Constraint::Type  type, const FitParams &  fitparams, Projection &  p  ) const

overridevirtualinherited

abstract abstract projection

Reimplemented from ParticleBase.

Definition at line 28 of file RecoParticle.cc.

  {
    ErrCode status ;
    switch (type) {
      case Constraint::track :
      case Constraint::photon :
      case Constraint::klong :
        status |= projectRecoConstraint(fitparams, p);
        break ;
      default:
        status |= ParticleBase::projectConstraint(type, fitparams, p);
    }
    return status;
  }

projectGeoConstraint()

ErrCode projectGeoConstraint ( const FitParams &  fitparams, Projection &  p  ) const

virtualinherited

project geometrical constraint

the direction of the momentum is very well known from the kinematic constraints that is why we do not extract the distance as a vector here

Definition at line 249 of file ParticleBase.cc.

  {
    assert(m_config);
    // only allow 2d for head of tree particles that are beam constrained
    const int dim = m_config->m_originDimension == 2 && std::abs(m_particle->getPDGCode()) == m_config->m_headOfTreePDG ? 2 : 3;
    const int posindexmother = mother()->posIndex();
    const int posindex = posIndex();
    const int tauindex = tauIndex();
    const int momindex = momIndex();
 
    const double tau = fitparams.getStateVector()(tauindex);
    Eigen::Matrix < double, 1, -1, 1, 1, 3 > x_vec = fitparams.getStateVector().segment(posindex, dim);
    Eigen::Matrix < double, 1, -1, 1, 1, 3 > x_m = fitparams.getStateVector().segment(posindexmother, dim);
    Eigen::Matrix < double, 1, -1, 1, 1, 3 > p_vec = fitparams.getStateVector().segment(momindex, dim);
    const double mom = p_vec.norm();
    const double mom3 = mom * mom * mom;
 
    if (3 == dim) {
      // we can already set these
      //diagonal momentum
      p.getH()(0, momindex)     = tau * (p_vec(1) * p_vec(1) + p_vec(2) * p_vec(2)) / mom3 ;
      p.getH()(1, momindex + 1) = tau * (p_vec(0) * p_vec(0) + p_vec(2) * p_vec(2)) / mom3 ;
      p.getH()(2, momindex + 2) = tau * (p_vec(0) * p_vec(0) + p_vec(1) * p_vec(1)) / mom3 ;
 
      //offdiagonal momentum
      p.getH()(0, momindex + 1) = - tau * p_vec(0) * p_vec(1) / mom3 ;
      p.getH()(0, momindex + 2) = - tau * p_vec(0) * p_vec(2) / mom3 ;
 
      p.getH()(1, momindex + 0) = - tau * p_vec(1) * p_vec(0) / mom3 ;
      p.getH()(1, momindex + 2) = - tau * p_vec(1) * p_vec(2) / mom3 ;
 
      p.getH()(2, momindex + 0) = - tau * p_vec(2) * p_vec(0) / mom3 ;
      p.getH()(2, momindex + 1) = - tau * p_vec(2) * p_vec(1) / mom3 ;
 
    } else if (2 == dim) {
 
      // NOTE THAT THESE ARE DIFFERENT IN 2d
      p.getH()(0, momindex)     = tau * (p_vec(1) * p_vec(1)) / mom3 ;
      p.getH()(1, momindex + 1) = tau * (p_vec(0) * p_vec(0)) / mom3 ;
 
      //offdiagonal momentum
      p.getH()(0, momindex + 1) = - tau * p_vec(0) * p_vec(1) / mom3 ;
      p.getH()(1, momindex + 0) = - tau * p_vec(1) * p_vec(0) / mom3 ;
    } else {
      B2FATAL("Dimension of Geometric constraint is not 2 or 3. This will crash many things. You should feel bad.");
    }
 
    for (int row = 0; row < dim; ++row) {
 
      double posxmother = x_m(row);
      double posx       = x_vec(row);
      double momx       = p_vec(row);
 
      p.getResiduals()(row) = posxmother + tau * momx / mom - posx ;
      p.getH()(row, posindexmother + row) = 1;
      p.getH()(row, posindex + row) = -1;
      p.getH()(row, tauindex) = momx / mom;
    }
 
    return ErrCode(ErrCode::Status::success);
  }

projectMassConstraint()

ErrCode projectMassConstraint ( const FitParams &  fitparams, Projection &  p  ) const

virtualinherited

project mass constraint abstract

Definition at line 405 of file ParticleBase.cc.

  {
    assert(m_config);
    if (m_config->m_massConstraintType == 0) {
      return projectMassConstraintParticle(fitparams, p);
    } else {
      return projectMassConstraintDaughters(fitparams, p);
    }
  }

projectMassConstraintDaughters()

ErrCode projectMassConstraintDaughters ( const FitParams &  fitparams, Projection &  p  ) const

virtualinherited

project mass constraint using the parameters of the daughters

be aware that the signs here are important E-|p|-m extracts a negative mass and messes with the momentum !

Definition at line 314 of file ParticleBase.cc.

  {
    const double mass = particle()->getPDGMass();
    const double mass2 = mass * mass;
    double px = 0;
    double py = 0;
    double pz = 0;
    double E  = 0;
 
    // the parameters of the daughters must be used otherwise the mass constraint does not have an effect on the extracted daughter momenta
    for (const auto* daughter : m_daughters) {
      const int momindex = daughter->momIndex();
      // in most cases the daughters will be final states so we cache the value to use it in the energy column
      const double px_daughter = fitparams.getStateVector()(momindex);
      const double py_daughter = fitparams.getStateVector()(momindex + 1);
      const double pz_daughter = fitparams.getStateVector()(momindex + 2);
 
      px += px_daughter;
      py += py_daughter;
      pz += pz_daughter;
      if (daughter->hasEnergy()) {
        E += fitparams.getStateVector()(momindex + 3);
      } else {
        // final states dont have an energy index
        const double m = daughter->particle()->getPDGMass();
        E += std::sqrt(m * m + px_daughter * px_daughter + py_daughter * py_daughter + pz_daughter * pz_daughter);
      }
    }
 
    p.getResiduals()(0) = mass2 - E * E + px * px + py * py + pz * pz;
 
    for (const auto* daughter : m_daughters) {
      //dr/dx = d/dx m2-{E1+E2+...}^2+{p1+p2+...}^2 = 2*x (x= E or p)
      const int momindex = daughter->momIndex();
      p.getH()(0, momindex)     = 2.0 * px;
      p.getH()(0, momindex + 1) = 2.0 * py;
      p.getH()(0, momindex + 2) = 2.0 * pz;
 
      if (daughter->hasEnergy()) {
        p.getH()(0, momindex + 3) = -2.0 * E;
      } else {
        const double px_daughter = fitparams.getStateVector()(momindex);
        const double py_daughter = fitparams.getStateVector()(momindex + 1);
        const double pz_daughter = fitparams.getStateVector()(momindex + 2);
        const double m = daughter->particle()->getPDGMass();
 
        const double E_daughter = std::sqrt(m * m + px_daughter * px_daughter + py_daughter * py_daughter + pz_daughter * pz_daughter);
        const double E_by_E_daughter = E / E_daughter;
        p.getH()(0, momindex)     -= 2.0 * E_by_E_daughter * px_daughter;
        p.getH()(0, momindex + 1) -= 2.0 * E_by_E_daughter * py_daughter;
        p.getH()(0, momindex + 2) -= 2.0 * E_by_E_daughter * pz_daughter;
      }
 
    }
    return ErrCode(ErrCode::Status::success);
  }

projectMassConstraintParticle()

ErrCode projectMassConstraintParticle ( const FitParams &  fitparams, Projection &  p  ) const

virtualinherited

project mass constraint using the particles parameters

be aware that the signs here are important E-|p|-m extracts a negative mass and messes with the momentum !

Definition at line 375 of file ParticleBase.cc.

  {
    const double mass = particle()->getPDGMass();
    const double mass2 = mass * mass;
    const int momindex = momIndex();
    const double px = fitparams.getStateVector()(momindex);
    const double py = fitparams.getStateVector()(momindex + 1);
    const double pz = fitparams.getStateVector()(momindex + 2);
    const double E  = fitparams.getStateVector()(momindex + 3);
 
    p.getResiduals()(0) = mass2 - E * E + px * px + py * py + pz * pz;
 
    p.getH()(0, momindex)     = 2.0 * px;
    p.getH()(0, momindex + 1) = 2.0 * py;
    p.getH()(0, momindex + 2) = 2.0 * pz;
    p.getH()(0, momindex + 3) = -2.0 * E;
 
    // TODO 0 in most cases -> needs special treatment if width=0 to not crash chi2 calculation
    // const double width = TDatabasePDG::Instance()->GetParticle(particle()->getPDGCode())->Width();
    // transport  measurement uncertainty into residual system
    // f' = sigma_x^2 * (df/dx)^2
    // p.getV()(0) = width * width * 4 * mass2;
 
    return ErrCode(ErrCode::Status::success);
  }

projectRecoConstraint()

ErrCode projectRecoConstraint ( const FitParams &  fitparams, Projection &  p  ) const

overridevirtual

project photon constraint

m : decay vertex mother p : momentum photon c : position cluster so: m + p = c thus (tau converts p to the correct units): 0 = c - m - tau * p we have 3 geometric equations and eliminate tau using the dimension with the highest momentum (because we have to divide by that momentum) only downside is we have to figure out which dimension this is the 4th equation is the energy which we keep as: 0 = E - |p| just to be sure, essentially this is always zero because p is build from E

Implements RecoParticle.

Definition at line 166 of file RecoPhoton.cc.

  {
    const int momindex = momIndex();
    const int posindex = mother()->posIndex();
    const Eigen::Matrix<double, 1, 3> x_vertex = fitparams.getStateVector().segment(posindex, 3);
    const Eigen::Matrix<double, 1, 3> p_vec = fitparams.getStateVector().segment(momindex, 3);
 
    if (0 == p_vec[m_i1]) {
      return ErrCode(ErrCode::photondimerror);
    }
 
    // p_vec[m_i1] must not be 0
    const double elim = (m_clusterPars[m_i1] - x_vertex[m_i1]) / p_vec[m_i1];
    const double mom = p_vec.norm();
 
    // r'
    Eigen::Matrix<double, 3, 1> residual3 = Eigen::Matrix<double, 3, 1>::Zero(3, 1);
    residual3(0) = m_clusterPars[m_i2] - x_vertex[m_i2] - p_vec[m_i2] * elim;
    residual3(1) = m_clusterPars[m_i3] - x_vertex[m_i3] - p_vec[m_i3] * elim;
    residual3(2) = m_momentumScalingFactor * m_clusterPars[3] - mom; // scale measured energy by scaling factor
 
    // dr'/dm | m:={xc,yc,zc,Ec} the measured quantities
    Eigen::Matrix<double, 3, 4> P = Eigen::Matrix<double, 3, 4>::Zero(3, 4);
    // deriving by the cluster pars
    P(0, m_i2) = 1;
    P(0, m_i1) = -p_vec[m_i2] / p_vec[m_i1];
 
    P(1, m_i3) = 1;
    P(1, m_i1) = -p_vec[m_i3] / p_vec[m_i1];
    P(2, 3) = 1; // dE/dEc
 
    p.getResiduals().segment(0, 3) = residual3;
 
    p.getV() = P * m_covariance.selfadjointView<Eigen::Lower>() * P.transpose();
 
    // dr'/dm  | m:={x,y,z,px,py,pz,E}
    // x := x_vertex (decay vertex of mother)
    p.getH()(0, posindex + m_i1) = p_vec[m_i2] / p_vec[m_i1];
    p.getH()(0, posindex + m_i2) = -1.0;
    p.getH()(0, posindex + m_i3) = 0;
 
    p.getH()(1, posindex + m_i1) = p_vec[m_i3] / p_vec[m_i1];
    p.getH()(1, posindex + m_i2) = 0;
    p.getH()(1, posindex + m_i3) = -1.0;
 
    // elim already divided by p_vec[m_i1]
    p.getH()(0, momindex + m_i1) = p_vec[m_i2] * elim / p_vec[m_i1];
    p.getH()(0, momindex + m_i2) = -1. * elim;
    p.getH()(0, momindex + m_i3) = 0;
 
    p.getH()(1, momindex + m_i1) = p_vec[m_i3] * elim / p_vec[m_i1];
    p.getH()(1, momindex + m_i2) = 0;
    p.getH()(1, momindex + m_i3) = -1. * elim;
 
    p.getH()(2, momindex + m_i1) = -1. * p_vec[m_i1] / mom;
    p.getH()(2, momindex + m_i2) = -1. * p_vec[m_i2] / mom;
    p.getH()(2, momindex + m_i3) = -1. * p_vec[m_i3] / mom;
    // the photon does not store an energy in the state vector
    // so no p.getH()(2, momindex + 3) here
 
    return ErrCode(ErrCode::Status::success);
  }

removeDaughter()

void removeDaughter ( const ParticleBase *  pb )

virtualinherited

remove daughter

Definition at line 73 of file ParticleBase.cc.

  {
    auto iter = std::find(m_daughters.begin(), m_daughters.end(), pb);
    if (iter != m_daughters.end()) {
      delete *iter;
      m_daughters.erase(iter);
    } else {
      B2ERROR("Cannot remove particle, because not found ...");
    }
  }

retrieveIndexMap()

void retrieveIndexMap ( indexmap &  anindexmap ) const

virtualinherited

get index map

Definition at line 223 of file ParticleBase.cc.

  {
    map.push_back(std::pair<const ParticleBase*, int>(this, index()));
    for (auto* daughter : m_daughters) {
      daughter->retrieveIndexMap(map);
    }
  }

setIndex()

void setIndex ( int  i )

inlineprotectedinherited

set Index (in statevector)

Definition at line 189 of file ParticleBase.h.

{ m_index = i ; }

setMother()

void setMother ( const ParticleBase *  m )

inlineinherited

set mother

Definition at line 164 of file ParticleBase.h.

{ m_mother = m ; }

tauIndex()

virtual int tauIndex ( ) const

inlinevirtualinherited

get tau index

Reimplemented in Composite, InternalParticle, Origin, RecoResonance, and Resonance.

Definition at line 125 of file ParticleBase.h.

{ return -1 ; }

type()

virtual int type ( ) const

inlineoverridevirtual

type

Implements ParticleBase.

Definition at line 50 of file RecoPhoton.h.

{ return kRecoPhoton ; }

updateIndex()

void updateIndex ( int &  offset )

virtualinherited

this sets the index for momentum, position, etc.

in the statevector

Definition at line 84 of file ParticleBase.cc.

  {
    for (auto* daughter : m_daughters) {
      daughter->updateIndex(offset);
    }
    m_index = offset;
    offset += dim();
  }

useEnergy()

bool useEnergy ( const Belle2::Particle &  cand )

static

has energy in fit params?

Definition at line 63 of file RecoPhoton.cc.

  {
    bool rc = true;
    const int pdg = particle.getPDGCode();
    if (pdg &&
        Belle2::Const::ParticleType(pdg) != Belle2::Const::photon &&
        Belle2::Const::ParticleType(pdg) != Belle2::Const::pi0) {
      rc = false;
    }
    return rc;
  }

Member Data Documentation

m_clusterPars

Eigen::Matrix<double, 1, 4> m_clusterPars

private

constrains measured params (x_c, y_c, z_c, E_c)

Definition at line 73 of file RecoPhoton.h.

m_config

const ConstraintConfiguration* m_config

protectedinherited

has all the constraint config

Definition at line 204 of file ParticleBase.h.

m_covariance

Eigen::Matrix<double, 4, 4> m_covariance

private

covariance (x_c,y_c,z_c,E_c) of measured pars

Definition at line 76 of file RecoPhoton.h.

m_daughters

std::vector<ParticleBase*> m_daughters

protectedinherited

daughter container

Definition at line 198 of file ParticleBase.h.

m_dim

const int m_dim

private

dimension of residuals and 'width' of H

Definition at line 64 of file RecoPhoton.h.

m_i1

int m_i1

private

index with the highest momentum.

We have to make sure this does not change during the fit.

Definition at line 79 of file RecoPhoton.h.

m_i2

int m_i2

private

random other index

Definition at line 81 of file RecoPhoton.h.

m_i3

int m_i3

private

another random index

Definition at line 83 of file RecoPhoton.h.

m_index

int m_index

privateinherited

index

Definition at line 208 of file ParticleBase.h.

m_init

bool m_init

private

was initialized*

Definition at line 67 of file RecoPhoton.h.

m_isStronglyDecayingResonance

bool m_isStronglyDecayingResonance

protectedinherited

decay length less than 1 micron

Definition at line 201 of file ParticleBase.h.

m_momentumScalingFactor

const float m_momentumScalingFactor

private

scale the momentum / energy by this correction factor

Definition at line 86 of file RecoPhoton.h.

m_mother

const ParticleBase* m_mother

protectedinherited

motherparticle

Definition at line 195 of file ParticleBase.h.

m_name

std::string m_name

privateinherited

name

Definition at line 211 of file ParticleBase.h.

m_particle

Belle2::Particle* m_particle

protectedinherited

pointer to framework type

Definition at line 192 of file ParticleBase.h.

m_useEnergy

bool m_useEnergy

private

has energy ins statevector

Definition at line 70 of file RecoPhoton.h.

---

The documentation for this class was generated from the following files:

• analysis/VertexFitting/TreeFitter/include/RecoPhoton.h
• analysis/VertexFitting/TreeFitter/src/RecoPhoton.cc