MultiTrackVertexLinkKinematicConstraint Class Reference

#include <MultiTrackVertexLinkKinematicConstraint.h>

Inheritance diagram for MultiTrackVertexLinkKinematicConstraint:

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

Private Attributes
GlobalPoint	refPoint

Detailed Description

This is an specialized version of MultiTrackVertexLinkKinematicConstraint. It constraints the sum of 4-vectors combined at a secondary vertex to be in parallel to the vertex link after considering the helix bend of the summed vector when propagating to the primary vertex.

Lars Perchalla, Philip Sauerland, July 2010

Definition at line 17 of file MultiTrackVertexLinkKinematicConstraint.h.

Constructor & Destructor Documentation

MultiTrackVertexLinkKinematicConstraint::MultiTrackVertexLinkKinematicConstraint ( GlobalPoint &  ref )

inline

Definition at line 20 of file MultiTrackVertexLinkKinematicConstraint.h.

References numberOfEquations(), parametersDerivative(), point, positionDerivative(), and value().

Referenced by clone().

                                                             :refPoint(ref)
    {}

Member Function Documentation

MultiTrackVertexLinkKinematicConstraint* MultiTrackVertexLinkKinematicConstraint::clone ( void  ) const

inlineoverridevirtual

Implements MultiTrackKinematicConstraint.

Definition at line 49 of file MultiTrackVertexLinkKinematicConstraint.h.

References MultiTrackVertexLinkKinematicConstraint().

    {
        return new MultiTrackVertexLinkKinematicConstraint(*this);
    }

int MultiTrackVertexLinkKinematicConstraint::numberOfEquations ( ) const

overridevirtual

Number of equations per track used for the fit

Implements MultiTrackKinematicConstraint.

Definition at line 121 of file MultiTrackVertexLinkKinematicConstraint.cc.

Referenced by MultiTrackVertexLinkKinematicConstraint().

                                                                    {
    return 2;
}

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

overridevirtual

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

Implements MultiTrackKinematicConstraint.

Definition at line 37 of file MultiTrackVertexLinkKinematicConstraint.cc.

References a, cuy::col, PVValHelper::dx, PVValHelper::dy, mps_fire::i, makeMuonMisalignmentScenario::matrix, pileupDistInMC::num, funct::pow(), PVValHelper::pT, refPoint, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and z.

Referenced by MultiTrackVertexLinkKinematicConstraint().

                                                                                                                                                    {
    int num = states.size();
    if(num<2) throw VertexException("MultiTrackVertexLinkKinematicConstraint::parametersDerivative <2 states passed");
    
    //2 equations (for all tracks)
    AlgebraicMatrix  matrix(2,num*7,0);//AlgebraicMatrix starts from 1
    double dx = point.x() - refPoint.x();
    double dy = point.y() - refPoint.y();
    double dT = sqrt(pow(dx,2) + pow(dy,2));
    
    double pxSum=0, pySum=0, pzSum=0;
    double aSum = 0;
    for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++)
    {
        double a = - i->particleCharge() * i->magneticField()->inInverseGeV(i->globalPosition()).z();
        aSum += a;

        pxSum += i->kinematicParameters()(3) - a*(point.y() - i->kinematicParameters()(1));
        pySum += i->kinematicParameters()(4) + a*(point.x() - i->kinematicParameters()(0));
        pzSum += i->kinematicParameters()(5);
    }

    double pT = sqrt(pow(pxSum,2) + pow(pySum,2));
    double pSum = sqrt(pow(pxSum,2) + pow(pySum,2) + pow(pzSum,2));

    int col=0;
    for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++){
        double a = - i->particleCharge() * i->magneticField()->inInverseGeV(i->globalPosition()).z();

        matrix(1,1+col*7) = a*(-(pT/pow(pySum,2)) + pxSum/pow(pySum,2) - (4*pySum)/(aSum*dT*sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2))) + (1 + (2*pySum)/(aSum*dT))/pT);//dH/dx
        matrix(1,2+col*7) = (a*(aSum*dT*(pT - pxSum) + 2*(-1 + (2*pT)/sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2)))*pxSum*pySum))/(aSum*dT*pT*pySum);//dH/dy
        //dH/dz=0
        matrix(1,4+col*7) = (aSum*dT*(pT - pxSum) + 2*(-1 + (2*pT)/sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2)))*pxSum*pySum)/(aSum*dT*pT*pySum);//dH/dpx
        matrix(1,5+col*7) = pT/pow(pySum,2) - pxSum/pow(pySum,2) + (4*pySum)/(aSum*dT*sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2))) + (-1 - (2*pySum)/(aSum*dT))/pT;//dH/dpy
        //dH/dpz=0
        //dH/dm=0
        matrix(2,1+col*7) = (a*(-pSum + pT)*pySum)/(pSum*pT*pzSum);//dH/dx
        matrix(2,2+col*7) = (a*( pSum - pT)*pxSum)/(pSum*pT*pzSum);//dH/dy
        //dH/dz
        matrix(2,4+col*7) = ((-(1/pSum) + 1/pT)*pxSum)/pzSum;//dH/dpx
        matrix(2,5+col*7) = ((-(1/pSum) + 1/pT)*pySum)/pzSum;//dH/dpy
        matrix(2,6+col*7) = -(1/pSum) + (pSum - pT)/pow(pzSum,2);//dH/dpz
        //dH/dm=0       
        
        col++;
    }
    
    return matrix;
}

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

overridevirtual

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

Implements MultiTrackKinematicConstraint.

Definition at line 87 of file MultiTrackVertexLinkKinematicConstraint.cc.

References a, PVValHelper::dx, PVValHelper::dy, PVValHelper::dz, mps_fire::i, makeMuonMisalignmentScenario::matrix, pileupDistInMC::num, funct::pow(), PVValHelper::pT, refPoint, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), z, and PV3DBase< T, PVType, FrameType >::z().

Referenced by MultiTrackVertexLinkKinematicConstraint().

                                                                                                                                                  {
    int num = states.size();
    if(num<2) throw VertexException("MultiTrackVertexLinkKinematicConstraint::positionDerivative <2 states passed");
    
    //2 equations (for all tracks)
    AlgebraicMatrix  matrix(2,3,0);
    double dx = point.x() - refPoint.x();
    double dy = point.y() - refPoint.y();
    double dz = point.z() - refPoint.z();
    double dT = sqrt(pow(dx,2) + pow(dy,2));
    double ds = sqrt(pow(dx,2) + pow(dy,2) + pow(dz,2));
    
    double pxSum=0, pySum=0, pzSum=0, aSum = 0;
    for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++){
        double a = - i->particleCharge() * i->magneticField()->inInverseGeV(i->globalPosition()).z();
        aSum += a;
        
        pxSum += i->kinematicParameters()(3) - a*(point.y() - i->kinematicParameters()(1));
        pySum += i->kinematicParameters()(4) + a*(point.x() - i->kinematicParameters()(0));
        pzSum += i->kinematicParameters()(5);
    }
    double pT = sqrt(pow(pxSum,2) + pow(pySum,2));
    double pSum = sqrt(pow(pxSum,2) + pow(pySum,2) + pow(pzSum,2));

    matrix(1,1) = (-1 + dx/dT)/dy + (2*dx*pT*(1 - (2*pT)/sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2))))/(aSum*pow(dT,3)) + aSum*(-(1/pT) + pT/pow(pySum,2) - pxSum/pow(pySum,2)) + (2*(-(1/pT) + 2/sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2)))*pySum)/dT;//dH/dxv
    matrix(1,2) = 1/dT + (-dT + dx)/pow(dy,2) - (dy*(-2*pT + sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2))))/(aSum*pow(dT,3)) - ((-2 + sqrt(4 - (pow(aSum,2)*pow(dT,2))/pow(pT,2)))*pxSum)/(dT*pT) - (aSum*(dy*pow(pT,2) + aSum*pow(dT,2)*pxSum))/(dT*pow(pT,2)*sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2))) + (aSum*(-pT + pxSum))/(pT*pySum);//dH/dyv
    //dH/dzv=0
    matrix(2,1) = ((1/ds - 1/dT)*dx)/dz + (aSum*(pSum - pT)*pySum)/(pSum*pT*pzSum);//dH/dxv
    matrix(2,2) = ((1/ds - 1/dT)*dy)/dz - (aSum*(pSum - pT)*pxSum)/(pSum*pT*pzSum);//dH/dyv
    matrix(2,3) = 1/ds + (-ds + dT)/pow(dz,2);//dH/dzv
    
    return matrix;
}

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

overridevirtual

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

Implements MultiTrackKinematicConstraint.

Definition at line 4 of file MultiTrackVertexLinkKinematicConstraint.cc.

References a, PVValHelper::dx, PVValHelper::dy, PVValHelper::dz, mps_fire::i, pileupDistInMC::num, funct::pow(), PVValHelper::pT, refPoint, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), z, and PV3DBase< T, PVType, FrameType >::z().

Referenced by MultiTrackVertexLinkKinematicConstraint().

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

    //2 equations (for all tracks)
    AlgebraicVector  vl(2,0);
    double dx = point.x() - refPoint.x();
    double dy = point.y() - refPoint.y();
    double dz = point.z() - refPoint.z();
    double dT = sqrt(pow(dx,2) + pow(dy,2));
    double ds = sqrt(pow(dx,2) + pow(dy,2) + pow(dz,2));

    double pxSum=0, pySum=0, pzSum=0;
    double aSum = 0;
    for(std::vector<KinematicState>::const_iterator i = states.begin(); i != states.end(); i++)
    {
        double a = - i->particleCharge() * i->magneticField()->inInverseGeV(i->globalPosition()).z();
        aSum += a;

        pxSum += i->kinematicParameters()(3) - a*(point.y() - i->kinematicParameters()(1));
        pySum += i->kinematicParameters()(4) + a*(point.x() - i->kinematicParameters()(0));
        pzSum += i->kinematicParameters()(5);
    }
    
    double pT = sqrt(pow(pxSum,2) + pow(pySum,2));
    double pSum = sqrt(pow(pxSum,2) + pow(pySum,2) + pow(pzSum,2));
    
    vl(1) = (dT - dx)/dy + (-2*pT + sqrt(-(pow(aSum,2)*pow(dT,2)) + 4*pow(pT,2)))/(aSum*dT) + (-pT + pxSum)/pySum;
    vl(2) = (ds - dT)/dz + (pT - pSum)/pzSum;
    
    return vl;
}

Member Data Documentation

GlobalPoint MultiTrackVertexLinkKinematicConstraint::refPoint

private

Definition at line 55 of file MultiTrackVertexLinkKinematicConstraint.h.

Referenced by parametersDerivative(), positionDerivative(), and value().