TwoBodyDecayTrajectoryState Class Reference

#include <TwoBodyDecayTrajectoryState.h>

Public Types
typedef std::pair < AlgebraicMatrix, AlgebraicMatrix >	Derivatives
typedef std::pair < TrajectoryStateOnSurface, TrajectoryStateOnSurface >	TsosContainer

Public Member Functions
const TwoBodyDecayParameters &	decayParameters (void) const
const Derivatives &	derivatives (void) const
bool	isValid (void) const
double	particleMass (void) const
double	primaryMass (void) const
double	primaryWidth (void) const
void	rescaleError (double scale)
const TsosContainer &	trajectoryStates (bool useRefittedState=true) const
	TwoBodyDecayTrajectoryState (const TsosContainer &tsos, const TwoBodyDecay &tbd, double particleMass, const MagneticField *magField, bool propagateErrors=false)
	~TwoBodyDecayTrajectoryState (void)

Private Member Functions
void	construct (const MagneticField *magField, bool propagateErrors)
bool	propagateSingleState (const FreeTrajectoryState &fts, const GlobalTrajectoryParameters &gtp, const AlgebraicMatrix &startDeriv, const Surface &surface, const MagneticField *magField, TrajectoryStateOnSurface &tsos, AlgebraicMatrix &endDeriv) const
void	setError (FreeTrajectoryState &fts, AlgebraicMatrix &derivative) const

Private Attributes
Derivatives	theDerivatives
TsosContainer	theOriginalTsos
TwoBodyDecayParameters	theParameters
double	theParticleMass
double	thePrimaryMass
double	thePrimaryWidth
TsosContainer	theRefittedTsos
bool	theValidityFlag

Static Private Attributes
static const unsigned int	nDecayParam = TwoBodyDecayParameters::dimension
static const unsigned int	nLocalParam = 5

Detailed Description

Definition at line 13 of file TwoBodyDecayTrajectoryState.h.

Member Typedef Documentation

typedef std::pair< AlgebraicMatrix, AlgebraicMatrix > TwoBodyDecayTrajectoryState::Derivatives

Definition at line 19 of file TwoBodyDecayTrajectoryState.h.

typedef std::pair< TrajectoryStateOnSurface, TrajectoryStateOnSurface > TwoBodyDecayTrajectoryState::TsosContainer

Definition at line 18 of file TwoBodyDecayTrajectoryState.h.

Constructor & Destructor Documentation

TwoBodyDecayTrajectoryState::TwoBodyDecayTrajectoryState	(	const TsosContainer &	tsos,
		const TwoBodyDecay &	tbd,
		double	particleMass,
		const MagneticField *	magField,
		bool	propagateErrors = false
	)

The constructor takes the two trajectory states that are to be updated (typically the innermost trajectory states of two tracks) and the decay parameters.

Definition at line 21 of file TwoBodyDecayTrajectoryState.cc.

References construct().

  : theValidityFlag( false ),
    theParticleMass( particleMass ),
    theParameters( tbd.decayParameters() ),
    theDerivatives( AlgebraicMatrix( nLocalParam, nDecayParam ), AlgebraicMatrix( nLocalParam, nDecayParam ) ),
    theOriginalTsos( tsos ),
    thePrimaryMass( tbd.primaryMass() ),
    thePrimaryWidth( tbd.primaryWidth() )
{
  construct( magField, propagateErrors );
}

TwoBodyDecayTrajectoryState::~TwoBodyDecayTrajectoryState ( void  )

inline

Definition at line 30 of file TwoBodyDecayTrajectoryState.h.

{}

Member Function Documentation

void TwoBodyDecayTrajectoryState::construct ( const MagneticField *  magField, bool  propagateErrors  )

private

Definition at line 47 of file TwoBodyDecayTrajectoryState.cc.

References TwoBodyDecayModel::cartesianSecondaryMomenta(), TwoBodyDecayDerivatives::derivatives(), derivatives(), TwoBodyDecayParameters::mass, p1, p2, propagateSingleState(), setError(), theDerivatives, theOriginalTsos, theParameters, theParticleMass, theRefittedTsos, theValidityFlag, TwoBodyDecayParameters::x, TwoBodyDecayParameters::y, and TwoBodyDecayParameters::z.

Referenced by TwoBodyDecayTrajectoryState().

{
  // construct global trajectory parameters at the starting point
  TwoBodyDecayModel tbdDecayModel( theParameters[TwoBodyDecayParameters::mass], theParticleMass );
  pair< AlgebraicVector, AlgebraicVector > secondaryMomenta = tbdDecayModel.cartesianSecondaryMomenta( theParameters );

  GlobalPoint vtx( theParameters[TwoBodyDecayParameters::x],
           theParameters[TwoBodyDecayParameters::y],
           theParameters[TwoBodyDecayParameters::z] );

  GlobalVector p1( secondaryMomenta.first[0],
           secondaryMomenta.first[1],
           secondaryMomenta.first[2] );

  GlobalVector p2( secondaryMomenta.second[0],
           secondaryMomenta.second[1],
           secondaryMomenta.second[2] );

  GlobalTrajectoryParameters gtp1( vtx, p1, theOriginalTsos.first.charge(), magField );
  FreeTrajectoryState fts1( gtp1 );

  GlobalTrajectoryParameters gtp2( vtx, p2, theOriginalTsos.second.charge(), magField );
  FreeTrajectoryState fts2( gtp2 );

  // contruct derivatives at the starting point
  TwoBodyDecayDerivatives tbdDerivatives( theParameters[TwoBodyDecayParameters::mass], theParticleMass );
  pair< AlgebraicMatrix, AlgebraicMatrix > derivatives = tbdDerivatives.derivatives( theParameters );

  AlgebraicMatrix deriv1( 6, 9, 0 );
  deriv1.sub( 1, 1, AlgebraicMatrix( 3, 3, 1 ) );
  deriv1.sub( 4, 4, derivatives.first );

  AlgebraicMatrix deriv2( 6, 9, 0 );
  deriv2.sub( 1, 1, AlgebraicMatrix( 3, 3, 1 ) );
  deriv2.sub( 4, 4, derivatives.second );

  // compute errors of initial states
  if ( propagateErrors ) {
    setError( fts1, deriv1 );
    setError( fts2, deriv2 );
  }


  // propgate states and derivatives from the starting points to the end points
  bool valid1 = propagateSingleState( fts1, gtp1, deriv1, theOriginalTsos.first.surface(),
                      magField, theRefittedTsos.first, theDerivatives.first );

  bool valid2 = propagateSingleState( fts2, gtp2, deriv2, theOriginalTsos.second.surface(),
                      magField, theRefittedTsos.second, theDerivatives.second );

  theValidityFlag = valid1 && valid2;

  return;
}

const TwoBodyDecayParameters& TwoBodyDecayTrajectoryState::decayParameters ( void  ) const

inline

Definition at line 35 of file TwoBodyDecayTrajectoryState.h.

References theParameters.

Referenced by TwoBodyDecayTrajectory::construct().

{ return theParameters; }

const Derivatives& TwoBodyDecayTrajectoryState::derivatives ( void  ) const

inline

Definition at line 37 of file TwoBodyDecayTrajectoryState.h.

References theDerivatives.

Referenced by TwoBodyDecayTrajectory::construct(), and construct().

{ return theDerivatives; }

bool TwoBodyDecayTrajectoryState::isValid ( void  ) const

inline

Definition at line 32 of file TwoBodyDecayTrajectoryState.h.

References theValidityFlag.

Referenced by TwoBodyDecayTrajectoryFactory::constructTrajectories().

{ return theValidityFlag; }

double TwoBodyDecayTrajectoryState::particleMass ( void  ) const

inline

Definition at line 34 of file TwoBodyDecayTrajectoryState.h.

References theParticleMass.

Referenced by TwoBodyDecayTrajectory::construct().

{ return theParticleMass; }

double TwoBodyDecayTrajectoryState::primaryMass ( void  ) const

inline

Definition at line 41 of file TwoBodyDecayTrajectoryState.h.

References thePrimaryMass.

Referenced by TwoBodyDecayTrajectory::construct().

{ return thePrimaryMass; }

double TwoBodyDecayTrajectoryState::primaryWidth ( void  ) const

inline

Definition at line 42 of file TwoBodyDecayTrajectoryState.h.

References thePrimaryWidth.

Referenced by TwoBodyDecayTrajectory::construct().

{ return thePrimaryWidth; }

bool TwoBodyDecayTrajectoryState::propagateSingleState ( const FreeTrajectoryState &  fts, const GlobalTrajectoryParameters &  gtp, const AlgebraicMatrix &  startDeriv, const Surface &  surface, const MagneticField *  magField, TrajectoryStateOnSurface &  tsos, AlgebraicMatrix &  endDeriv  ) const

private

Definition at line 104 of file TwoBodyDecayTrajectoryState.cc.

References AnalyticalPropagator_cfi::AnalyticalPropagator, asHepMatrix(), JacobianCartesianToCurvilinear::jacobian(), JacobianCurvilinearToLocal::jacobian(), and AnalyticalCurvilinearJacobian::jacobian().

Referenced by construct().

{
  AnalyticalPropagator propagator( magField );

  // propagate state
  pair< TrajectoryStateOnSurface, double > tsosWithPath = propagator.propagateWithPath( fts, surface );

  // check if propagation was successful
  if ( !tsosWithPath.first.isValid() ) return false;

  // jacobian for transformation from cartesian to curvilinear frame at the starting point
  JacobianCartesianToCurvilinear cartToCurv( gtp );
  const AlgebraicMatrix56& matCartToCurv = cartToCurv.jacobian();

  // jacobian in curvilinear frame for propagation from the starting point to the end point
  AnalyticalCurvilinearJacobian curvJac( gtp, tsosWithPath.first.globalPosition(),
                     tsosWithPath.first.globalMomentum(),
                     tsosWithPath.second );
  const AlgebraicMatrix55& matCurvJac = curvJac.jacobian();

  // jacobian for transformation from curvilinear to local frame at the end point
  JacobianCurvilinearToLocal curvToLoc( surface, tsosWithPath.first.localParameters(), *magField );
  const AlgebraicMatrix55& matCurvToLoc = curvToLoc.jacobian();

  AlgebraicMatrix56 tmpDeriv = matCurvToLoc*matCurvJac*matCartToCurv;
  AlgebraicMatrix hepMatDeriv( asHepMatrix( tmpDeriv ) );
  //AlgebraicMatrix hepMatDeriv = asHepMatrix< 5, 6 >( tmpDeriv );

  // replace original state with new state
  tsos = tsosWithPath.first;

  // propagate derivative matrix
  endDeriv = hepMatDeriv*startDeriv;

  return true;
}

void TwoBodyDecayTrajectoryState::rescaleError

(

double

scale

)

Definition at line 38 of file TwoBodyDecayTrajectoryState.cc.

References theOriginalTsos, and theRefittedTsos.

{
  theOriginalTsos.first.rescaleError( scale );
  theOriginalTsos.second.rescaleError( scale );
  theRefittedTsos.first.rescaleError( scale );
  theRefittedTsos.second.rescaleError( scale );
}

void TwoBodyDecayTrajectoryState::setError ( FreeTrajectoryState &  fts, AlgebraicMatrix &  derivative  ) const

private

Definition at line 148 of file TwoBodyDecayTrajectoryState.cc.

References TwoBodyDecayParameters::covariance(), FreeTrajectoryState::setCartesianError(), and theParameters.

Referenced by construct().

{
  AlgebraicSymMatrix ftsCartesianError( theParameters.covariance().similarity( derivative ) );
  fts.setCartesianError( asSMatrix<6>( ftsCartesianError ) );
}

const TsosContainer& TwoBodyDecayTrajectoryState::trajectoryStates ( bool  useRefittedState = true ) const

inline

Definition at line 36 of file TwoBodyDecayTrajectoryState.h.

References theOriginalTsos, and theRefittedTsos.

Referenced by TwoBodyDecayTrajectory::construct(), and TwoBodyDecayTrajectoryFactory::constructTrajectories().

{ return useRefittedState ? theRefittedTsos : theOriginalTsos; }

Member Data Documentation

const unsigned int TwoBodyDecayTrajectoryState::nDecayParam = TwoBodyDecayParameters::dimension

staticprivate

Definition at line 74 of file TwoBodyDecayTrajectoryState.h.

const unsigned int TwoBodyDecayTrajectoryState::nLocalParam = 5

staticprivate

Definition at line 73 of file TwoBodyDecayTrajectoryState.h.

Derivatives TwoBodyDecayTrajectoryState::theDerivatives

private

Definition at line 66 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), and derivatives().

TsosContainer TwoBodyDecayTrajectoryState::theOriginalTsos

private

Definition at line 67 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), rescaleError(), and trajectoryStates().

TwoBodyDecayParameters TwoBodyDecayTrajectoryState::theParameters

private

Definition at line 65 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), decayParameters(), and setError().

double TwoBodyDecayTrajectoryState::theParticleMass

private

Definition at line 63 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), and particleMass().

double TwoBodyDecayTrajectoryState::thePrimaryMass

private

Definition at line 70 of file TwoBodyDecayTrajectoryState.h.

Referenced by primaryMass().

double TwoBodyDecayTrajectoryState::thePrimaryWidth

private

Definition at line 71 of file TwoBodyDecayTrajectoryState.h.

Referenced by primaryWidth().

TsosContainer TwoBodyDecayTrajectoryState::theRefittedTsos

private

Definition at line 68 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), rescaleError(), and trajectoryStates().

bool TwoBodyDecayTrajectoryState::theValidityFlag

private

Definition at line 61 of file TwoBodyDecayTrajectoryState.h.

Referenced by construct(), and isValid().