FourHitFilters Class Reference

The class 'FourHitFilters' bundles filter methods using 4 hits which are stored in B2Vector3Ds. More...

#include <FourHitFilters.h>

Collaboration diagram for FourHitFilters:

Public Member Functions
	FourHitFilters ()
	Empty constructor. More...
	FourHitFilters (const B2Vector3D &outer, const B2Vector3D &outerCenter, const B2Vector3D &innerCenter, const B2Vector3D &inner, const double magneticFieldStrength=1.5)
	Constructor. More...
	~FourHitFilters ()
	Destructor.
void	resetValues (const B2Vector3D &outer, const B2Vector3D &outerCenter, const B2Vector3D &innerCenter, const B2Vector3D &inner)
	Overrides Constructor-Setup. More...
void	resetMagneticField (const double magneticFieldStrength=1.5)
	Overrides Constructor-Setup for magnetic field. More...
double	calcDeltapT ()
	calculates dpt-value (dpt= difference in transverse momentum of 2 subsets of the hits), returning unit: GeV/c More...
double	deltapT ()
	legacy - compatibility for old cases
double	calcDeltaDistCircleCenter ()
	calculates ddist2IP-value directly (ddist2IP= difference in magnitude of the points of closest approach of two circles calculated using 2 subsets of the hits)
double	deltaDistCircleCenter ()
	legacy - compatibility for old cases

Protected Member Functions
void	calcCircle ()
	calculates an estimation of circleCenter position including an estimation for the circle radius

Protected Attributes
B2Vector3D	m_hitA
	outer hit (position relevant for useful filter calculation) used for the filter calculation
B2Vector3D	m_hitB
	outerCenter hit (position relevant for useful filter calculation) used for the filter calculation
B2Vector3D	m_hitC
	innerCenter hit (position relevant for useful filter calculation) used for the filter calculation
B2Vector3D	m_hitD
	inner hit (position relevant for useful filter calculation) used for the filter calculation
B2Vector3D	m_centerABC
	estimation of a circleCenterPosition using hits A, B & C
B2Vector3D	m_centerBCD
	estimation of a circleCenterPosition using hitsBA, C & D
double	m_radiusABC
	estimation of the radius of the circle using hits A, B & C
double	m_radiusBCD
	estimation of a radius of the circle using hitsBA, C & D
ThreeHitFilters	m_threeHitFilter
	instance of ThreeHitFilters-class used for some internal calculations
bool	m_circleCalculated
	initially set to false, will be set true if calcCircle() is used at least once

Detailed Description

The class 'FourHitFilters' bundles filter methods using 4 hits which are stored in B2Vector3Ds.

Definition at line 23 of file FourHitFilters.h.

Constructor & Destructor Documentation

FourHitFilters() [1/2]

FourHitFilters ( )

inline

Empty constructor.

For initialisation only, an object generated this way is useless unless resetValues(a, b) is called at least once

Definition at line 28 of file FourHitFilters.h.

                    :
      m_radiusABC(0.),
      m_radiusBCD(0.),
      m_circleCalculated(false) {}

FourHitFilters() [2/2]

FourHitFilters ( const B2Vector3D &  outer, const B2Vector3D &  outerCenter, const B2Vector3D &  innerCenter, const B2Vector3D &  inner, const double  magneticFieldStrength = 1.5  )

inline

Constructor.

expects 4 hits in B2Vector3D format, first parameter is outer hit, second is outerCenter hit, third is innercenter hit, last one is the innermost hit, optional parameter sets strength of magnetic field (standard is 1.5T)

Definition at line 34 of file FourHitFilters.h.

Member Function Documentation

calcDeltapT()

double calcDeltapT

(

)

calculates dpt-value (dpt= difference in transverse momentum of 2 subsets of the hits), returning unit: GeV/c

TODO: evtly do a 'nan'-check for return values.

Definition at line 17 of file FourHitFilters.cc.

{
  if (m_circleCalculated == false) { calcCircle(); }
  return fabs(m_threeHitFilter.calcPt(m_radiusABC -
                                      m_radiusBCD)); // , or, pT[GeV/c] = 0.299710*B[T]*r[m] = 0,449565*r[cm]/100 = 0.00449565*r[cm]
}

resetMagneticField()

void resetMagneticField ( const double  magneticFieldStrength = 1.5 )

inline

Overrides Constructor-Setup for magnetic field.

if no value is given, magnetic field is assumed to be Belle2-Detector standard of 1.5T

Definition at line 61 of file FourHitFilters.h.

resetValues()

void resetValues ( const B2Vector3D &  outer, const B2Vector3D &  outerCenter, const B2Vector3D &  innerCenter, const B2Vector3D &  inner  )

inline

Overrides Constructor-Setup.

Needed if you want to reuse the instance instead of recreating one

Definition at line 49 of file FourHitFilters.h.

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

• tracking/vxdCaTracking/include/FourHitFilters.h
• tracking/vxdCaTracking/src/FourHitFilters.cc