VertexKinematicConstraint Class Reference

#include <VertexKinematicConstraint.h>

Inheritance diagram for VertexKinematicConstraint:

Public Member Functions
virtual VertexKinematicConstraint *	clone () const
virtual int	numberOfEquations () const
virtual AlgebraicMatrix	parametersDerivative (const std::vector< KinematicState > states, const GlobalPoint &point) const
virtual AlgebraicMatrix	positionDerivative (const std::vector< KinematicState > states, const GlobalPoint &point) const
virtual AlgebraicVector	value (const std::vector< KinematicState > states, const GlobalPoint &point) const
	VertexKinematicConstraint ()
virtual	~VertexKinematicConstraint ()
Public Member Functions inherited from MultiTrackKinematicConstraint
	MultiTrackKinematicConstraint ()
virtual	~MultiTrackKinematicConstraint ()

Detailed Description

Class implementing the vertexing constraint for extended cartesian parametrization (x,y,z,p_x,p_y,p_z,m). The equations and derivatives in general follow the P.Avery's "Applied Fitting Theory-VI" CBX 98-37

Definition at line 14 of file VertexKinematicConstraint.h.

Constructor & Destructor Documentation

VertexKinematicConstraint::VertexKinematicConstraint

(

)

Definition at line 5 of file VertexKinematicConstraint.cc.

Referenced by clone().

{}

VertexKinematicConstraint::~VertexKinematicConstraint ( )

virtual

Definition at line 8 of file VertexKinematicConstraint.cc.

{}

Member Function Documentation

virtual VertexKinematicConstraint* VertexKinematicConstraint::clone ( void  ) const

inlinevirtual

Implements MultiTrackKinematicConstraint.

Definition at line 50 of file VertexKinematicConstraint.h.

References VertexKinematicConstraint().

{return new VertexKinematicConstraint(*this);}

int VertexKinematicConstraint::numberOfEquations ( ) const

virtual

Number of equations per track used for the fit

Implements MultiTrackKinematicConstraint.

Definition at line 170 of file VertexKinematicConstraint.cc.

{return 2;}

AlgebraicMatrix VertexKinematicConstraint::parametersDerivative ( const std::vector< KinematicState >  states, const GlobalPoint &  point  ) const

virtual

Returns a matrix of derivatives of constraint equations w.r.t. particle parameters

Implements MultiTrackKinematicConstraint.

Definition at line 56 of file VertexKinematicConstraint.cc.

References delta, i, gen::k, m, n, pos, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::transverse(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by KinematicConstrainedVertexUpdator::update().

{
  int num = states.size();
  if(num<2) throw VertexException("VertexKinematicConstraint::<2 states passed");
  AlgebraicMatrix jac_d(2*num,7*num);
  int num_r = 0;
  for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++)
  {
    AlgebraicMatrix el_part_d(2,7,0);
    TrackCharge ch = i->particleCharge();
    GlobalVector mom = i->globalMomentum();
    GlobalPoint pos =  i->globalPosition();
    double d_x = point.x() - pos.x();
    double d_y = point.y() - pos.y();
    double pt = mom.transverse();
    
    if(ch !=0){

  //charged particle
   double a_i = - ch * i->magneticField()->inInverseGeV(pos).z();
   
   double pvx = mom.x() - a_i*d_y;
   double pvy = mom.y() + a_i*d_x;
   double pvt = sqrt(pvx*pvx+pvy*pvy);
   double novera = (d_x * mom.x() + d_y * mom.y());
   double n = a_i*novera;
   double m = (pvx*mom.x() + pvy*mom.y());
   double k = -mom.z()/(pvt*pvt*pt*pt);
   double delta = atan2(n,m);

  //D Jacobian matrix
     el_part_d(1,1) =  mom.y() + a_i*d_x;
     el_part_d(1,2) = -mom.x() + a_i*d_y;
     el_part_d(2,1) =  -k*(m*mom.x() - n*mom.y());
     el_part_d(2,2) =  -k*(m*mom.y() + n*mom.x());
     el_part_d(2,3) = -1.;
     el_part_d(1,4) = d_y;
     el_part_d(1,5) = -d_x;
     el_part_d(2,4) = k*(m*d_x - novera*(2*mom.x() - a_i*d_y));
     el_part_d(2,5) = k*(m*d_y - novera*(2*mom.y() + a_i*d_x));
     el_part_d(2,6) = -delta /a_i;
     jac_d.sub(num_r*2+1, num_r*7+1, el_part_d);
    }else{
  //neutral particle
      el_part_d(1,1) =  mom.y();
      el_part_d(1,2) = -mom.x();
      el_part_d(2,1) =  mom.x() * mom.z()/(pt*pt);
      el_part_d(2,2) =  mom.y() * mom.z()/(pt*pt);
      el_part_d(2,3) = -1.;
      el_part_d(1,4) = d_y;
      el_part_d(1,5) = -d_x;
      el_part_d(2,4) = 2*(d_x*mom.x()+d_y*mom.y())*mom.x()*mom.z()/(pt*pt*pt*pt) - mom.z()*d_x/(pt*pt);
      el_part_d(2,5) = 2*(d_x*mom.x()+d_y*mom.y())*mom.y()*mom.z()/(pt*pt*pt*pt) - mom.z()*d_y/(pt*pt);
      el_part_d(2,6) =-(d_x * mom.x() + d_y * mom.y())/(pt*pt);
      jac_d.sub(num_r*2+1, num_r*7+1, el_part_d);
    }
    num_r++;
  }
  return jac_d;
}

AlgebraicMatrix VertexKinematicConstraint::positionDerivative ( const std::vector< KinematicState >  states, const GlobalPoint &  point  ) const

virtual

Returns a matrix of derivatives of constraint equations w.r.t. vertex position

Implements MultiTrackKinematicConstraint.

Definition at line 118 of file VertexKinematicConstraint.cc.

References i, gen::k, m, n, pos, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::transverse(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by KinematicConstrainedVertexUpdator::update().

{
 int num = states.size();
 if(num<2) throw VertexException("VertexKinematicConstraint::<2 states passed");
 AlgebraicMatrix jac_e(2*num,3);
 int num_r = 0;
 for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++)
 {
  AlgebraicMatrix el_part_e(2,3,0);
  TrackCharge ch = i->particleCharge();
  GlobalVector mom = i->globalMomentum();
  GlobalPoint pos =  i->globalPosition();
  double d_x = point.x() - pos.x();
  double d_y = point.y() - pos.y();
  double pt = mom.transverse();
  
  if(ch !=0 )
  {

//charged particle
   double a_i = - ch * i->magneticField()->inInverseGeV(pos).z();

   double pvx = mom.x() - a_i*d_y;
   double pvy = mom.y() + a_i*d_x;
   double pvt = sqrt(pvx*pvx+pvy*pvy);
   double n = a_i*(d_x * mom.x() + d_y * mom.y());
   double m = (pvx*mom.x() + pvy*mom.y());
   double k = -mom.z()/(pvt*pvt*pt*pt);

//E jacobian matrix
   el_part_e(1,1) = -(mom.y() + a_i*d_x);
   el_part_e(1,2) = mom.x() - a_i*d_y;
   el_part_e(2,1) = k*(m*mom.x() - n*mom.y());
   el_part_e(2,2) = k*(m*mom.y() + n*mom.x());
   el_part_e(2,3) = 1;
   jac_e.sub(2*num_r+1,1,el_part_e);
  }else{

//neutral particle
   el_part_e(1,1) = - mom.y();
   el_part_e(1,2) = mom.x();
   el_part_e(2,1) = -mom.x()*mom.z()/(pt*pt);
   el_part_e(2,2) = -mom.y()*mom.z()/(pt*pt);
   el_part_e(2,3) = 1;
   jac_e.sub(2*num_r+1,1,el_part_e);
  }
  num_r++;
 }
 return jac_e;
}

AlgebraicVector VertexKinematicConstraint::value ( const std::vector< KinematicState >  states, const GlobalPoint &  point  ) const

virtual

Returns a vector of values of constraint equations at the point where the input particles are defined.

Implements MultiTrackKinematicConstraint.

Definition at line 11 of file VertexKinematicConstraint.cc.

References delta, i, m, n, pos, PV3DBase< T, PVType, FrameType >::transverse(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by KinematicConstrainedVertexUpdator::update().

{
 int num = states.size();
 if(num<2) throw VertexException("VertexKinematicConstraint::<2 states passed");

//it is 2 equations per track
 AlgebraicVector  vl(2*num,0);
 int num_r = 0;
 for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++)
 {
  TrackCharge ch = i->particleCharge();
  GlobalVector mom = i->globalMomentum();
  GlobalPoint pos =  i->globalPosition();
  double d_x = point.x() - pos.x();
  double d_y = point.y() - pos.y();
  double d_z = point.z() - pos.z();
  double pt = mom.transverse();
  
  if(ch !=0)
  {

//charged particle
   double a_i = - ch * i->magneticField()->inInverseGeV(pos).z();

   double pvx = mom.x() - a_i*d_y;
   double pvy = mom.y() + a_i*d_x;
   double n = a_i*(d_x * mom.x() + d_y * mom.y());
   double m = (pvx*mom.x() + pvy*mom.y());
   double delta = atan2(n,m);

//vector of values
   vl(num_r*2 +1) = d_y*mom.x() - d_x*mom.y() -a_i*(d_x*d_x + d_y*d_y)/2;
   vl(num_r*2 +2) = d_z - mom.z()*delta/a_i;
  }else{

//neutral particle
   vl(num_r*2 +1) = d_y*mom.x() - d_x*mom.y();
   vl(num_r*2 +2) = d_z - mom.z()*(d_x * mom.x() + d_y * mom.y())/(pt*pt);
  }
  num_r++;
 }
 return vl;
}