Composite Class Reference

A class for composite particles, where the daughters must be ignored by the fitter. More...

#include <Composite.h>

Inheritance diagram for Composite:

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
	Composite (Belle2::Particle *bc, const ParticleBase *mother, const ConstraintConfiguration &config, bool massconstraint=false)
	constructor
virtual	~Composite ()
	destructor
virtual ErrCode	initParticleWithMother (FitParams &fitparams) override
	init particle in case it has a mother
virtual ErrCode	initMotherlessParticle (FitParams &fitparams) override
	init particle in case it has no mother
void	updateParams ()
	update changed params
ErrCode	projectComposite (const FitParams &fitparams, Projection &p) const
	project this particle constraint
int	dimMeas () const
	dimension of the measurement vector
virtual int	dim () const override
	get dimension of constraint
int	dimM () const
	get dimension of measurement
virtual ErrCode	projectConstraint (Constraint::Type, const FitParams &, Projection &) const override
	project this constraint
virtual int	type () const override
	get ype
virtual int	posIndex () const override
	get position index in statevectof x,y,z,tau,px,py,pz
virtual int	tauIndex () const override
	get tau (lifetime) index in statevector
virtual int	momIndex () const override
	get momentum index in statevector
virtual bool	hasEnergy () const override
	return of this constraint/particle has an energy component
virtual bool	hasPosition () const override
	return true FIXME
virtual void	addToConstraintList (constraintlist &alist, int depth) const override
	add this to list
virtual ErrCode	initCovariance (FitParams &) const
	init covariance matrix
virtual void	updateIndex (int &offset)
	this sets the index for momentum, position, etc.
virtual std::string	parname (int index) const
	get name of parameter i
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
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 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
Eigen::Matrix< double, 7, 1 >	m_params
	column vector to store the measurement
Eigen::Matrix< double, -1, -1, 0, 7, 7 >	m_covariance
	only lower triangle filled!
bool	m_hasEnergy
	flag
bool	m_massconstraint
	flag
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
int	m_index
	index
std::string	m_name
	name

Detailed Description

A class for composite particles, where the daughters must be ignored by the fitter.

Currently used for bremsstrahlung correction and dummy invisibles

Definition at line 17 of file Composite.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

Composite()

Composite	(	Belle2::Particle *	bc,
		const ParticleBase *	mother,
		const ConstraintConfiguration &	config,
		bool	massconstraint = false
	)

constructor

Definition at line 19 of file Composite.cc.

    : ParticleBase(particle, mother, &config), m_params(), m_hasEnergy(true), m_massconstraint(massConstraint)
  {
    updateParams();
  }

~Composite()

virtual ~Composite ( )

inlinevirtual

destructor

Definition at line 25 of file Composite.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 this to list

Implements ParticleBase.

Reimplemented in RecoResonance.

Definition at line 70 of file Composite.h.

    {
      alist.push_back(Constraint(this, Constraint::composite, depth, dimM())) ;
      alist.push_back(Constraint(this, Constraint::geometric, depth, 3)) ;
      if (m_massconstraint) {
        alist.push_back(Constraint(this, Constraint::mass, depth, 1, 3));
      }
    }

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

get dimension of constraint

Implements ParticleBase.

Reimplemented in RecoResonance.

Definition at line 43 of file Composite.h.

{ return m_hasEnergy ? 8 : 7 ; }// (x,y,z,t,px,py,pz,(E))

dimM()

int dimM ( ) const

inline

get dimension of measurement

Definition at line 46 of file Composite.h.

{ return m_hasEnergy ? 7 : 6 ; }

dimMeas()

int dimMeas ( ) const

inline

dimension of the measurement vector

Definition at line 40 of file Composite.h.

{ return m_hasEnergy ? 7 : 6 ; }

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

return of this constraint/particle has an energy component

Reimplemented from ParticleBase.

Definition at line 64 of file Composite.h.

{ return m_hasEnergy ; }

hasPosition()

virtual bool hasPosition ( ) const

inlineoverridevirtual

return true FIXME

Reimplemented from ParticleBase.

Definition at line 67 of file Composite.h.

{ return true ; }

index()

int index ( ) const

inlineinherited

get index

Definition at line 95 of file ParticleBase.h.

{ return m_index ; }

initCovariance()

ErrCode initCovariance ( FitParams &  fitparams ) const

virtualinherited

init covariance matrix

Reimplemented in InternalParticle, Origin, RecoKlong, RecoPhoton, and RecoTrack.

Definition at line 167 of file ParticleBase.cc.

  {
    // this is very sensitive and can heavily affect the efficiency of the fit
    ErrCode status;
 
    const int posindex = posIndex();
    if (posindex >= 0) {
      for (int i = 0; i < 3; ++i) {
        fitparams.getCovariance()(posindex + i, posindex + i) = 1;
      }
    }
 
    const int momindex = momIndex();
    if (momindex >= 0) {
      const int maxrow = hasEnergy() ? 4 : 3;
      for (int i = 0; i < maxrow; ++i) {
        fitparams.getCovariance()(momindex + i, momindex + i) = 10.;
      }
    }
 
    const int tauindex = tauIndex();
    if (tauindex >= 0) {
      fitparams.getCovariance()(tauindex, tauindex) = 1.;
    }
    return status;
  }

initMotherlessParticle()

ErrCode initMotherlessParticle ( FitParams &  fitparams )

overridevirtual

init particle in case it has no mother

Implements ParticleBase.

Reimplemented in RecoResonance.

Definition at line 31 of file Composite.cc.

  {
    const int posindex = posIndex();
    const int momindex = momIndex();
 
    fitparams.getStateVector().segment(posindex, 3) = m_params.segment(0, 3);
 
    fitparams.getStateVector().segment(momindex, 4) = m_params.segment(3, 4);
 
    return ErrCode(ErrCode::Status::success) ;
  }

initParticleWithMother()

ErrCode initParticleWithMother ( FitParams &  fitparams )

overridevirtual

init particle in case it has a mother

Implements ParticleBase.

Reimplemented in RecoResonance.

Definition at line 26 of file Composite.cc.

  {
    return initTau(fitparams);
  }

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

inlineoverridevirtual

get momentum index in statevector

Reimplemented from ParticleBase.

Reimplemented in RecoResonance.

Definition at line 61 of file Composite.h.

{ return index() + 4 ; }

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

virtualinherited

get name of parameter i

Reimplemented in InternalParticle, RecoParticle, RecoResonance, and Resonance.

Definition at line 194 of file ParticleBase.cc.

  {
    std::string rc = m_name;
    switch (thisindex) {
      case 0: rc += "_x  "; break;
      case 1: rc += "_y  "; break;
      case 2: rc += "_z  "; break;
      case 3: rc += "_tau"; break;
      case 4: rc += "_px "; break;
      case 5: rc += "_py "; break;
      case 6: rc += "_pz "; break;
      case 7: rc += "_E  "; break;
      default:;
    }
    return rc;
  }

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

inlineoverridevirtual

get position index in statevectof x,y,z,tau,px,py,pz

Reimplemented from ParticleBase.

Reimplemented in RecoResonance.

Definition at line 55 of file Composite.h.

{ return index()   ; }

projectComposite()

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

project this particle constraint

Definition at line 75 of file Composite.cc.

  {
    const int posindex = posIndex() ;
    const int momindex = momIndex() ;
 
    p.getResiduals().segment(0, 3) = m_params.segment(0, 3) - fitparams.getStateVector().segment(posindex, 3);
 
    p.getResiduals().segment(3, 4) = m_params.segment(3, 4) - fitparams.getStateVector().segment(momindex, 4);
 
    for (int row = 0; row < 3; ++row) {
      p.getH()(row,  posindex + row) = -1;
    }
 
    for (int row = 0; row < 4; ++row) {
      p.getH()(3 + row,  momindex + row) = -1;
    }
 
    p.getV().triangularView<Eigen::Lower>() = m_covariance.triangularView<Eigen::Lower>();
 
    return ErrCode(ErrCode::Status::success) ;
  }

projectConstraint()

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

overridevirtual

project this constraint

Reimplemented from ParticleBase.

Reimplemented in RecoResonance.

Definition at line 97 of file Composite.cc.

  {
    ErrCode status;
    switch (type) {
      case Constraint::mass:
        status |= projectMassConstraint(fitparams, p);
        break;
      case Constraint::composite:
        status |= projectComposite(fitparams, p);
        break ;
      case Constraint::geometric:
        status |= projectGeoConstraint(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);
  }

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

inlineoverridevirtual

get tau (lifetime) index in statevector

Reimplemented from ParticleBase.

Reimplemented in RecoResonance.

Definition at line 58 of file Composite.h.

{ return index() + 3 ; }

type()

virtual int type ( ) const

inlineoverridevirtual

get ype

Implements ParticleBase.

Reimplemented in RecoResonance.

Definition at line 52 of file Composite.h.

{ return kComposite ; }

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();
  }

updateParams()

void updateParams

(

)

update changed params

Definition at line 43 of file Composite.cc.

  {
    const ROOT::Math::XYZVector pos = particle()->getVertex();
    const ROOT::Math::XYZVector mom = particle()->getMomentum();
    const double energy = particle()->getEnergy();
 
    m_params = Eigen::Matrix<double, 7, 1>::Zero(7, 1);
    m_params(0) = pos.X();
    m_params(1) = pos.Y();
    m_params(2) = pos.Z();
    m_params(3) = mom.X();
    m_params(4) = mom.Y();
    m_params(5) = mom.Z();
 
    m_params(6) = energy;
 
    m_covariance = Eigen::Matrix < double, -1, -1, 0, 7, 7 >::Zero(7, 7);
    const TMatrixFSym cov7in = particle()->getMomentumVertexErrorMatrix(); //this is (p,E,x)
 
    for (int row = 0; row < 4; ++row) { //first the p,E block
      for (int col = 0; col <= row; ++col) {
        m_covariance(3 + row, 3 + col) = cov7in[row][col];
      }
    }
 
    for (int row = 0; row < 3; ++row) { //then the x block
      for (int col = 0; col <= row; ++col) {
        m_covariance(row, col) = cov7in[4 + row][4 + col];
      }
    }
  }

Member Data Documentation

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, -1, -1, 0, 7, 7 > m_covariance

protected

only lower triangle filled!

Definition at line 85 of file Composite.h.

m_daughters

std::vector<ParticleBase*> m_daughters

protectedinherited

daughter container

Definition at line 198 of file ParticleBase.h.

m_hasEnergy

bool m_hasEnergy

protected

flag

Definition at line 88 of file Composite.h.

m_index

int m_index

privateinherited

index

Definition at line 208 of file ParticleBase.h.

m_isStronglyDecayingResonance

bool m_isStronglyDecayingResonance

protectedinherited

decay length less than 1 micron

Definition at line 201 of file ParticleBase.h.

m_massconstraint

bool m_massconstraint

protected

flag

Definition at line 91 of file Composite.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_params

Eigen::Matrix<double, 7, 1> m_params

protected

column vector to store the measurement

Definition at line 82 of file Composite.h.

m_particle

Belle2::Particle* m_particle

protectedinherited

pointer to framework type

Definition at line 192 of file ParticleBase.h.

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

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