PathToPlane2Order Class Reference

#include <PathToPlane2Order.h>

Public Types
typedef GloballyPositioned< Scalar >	Frame
typedef Plane::Scalar	Scalar
typedef Basic3DVector< Scalar >	Vector3D

Public Member Functions
std::pair< bool, double >	operator() (const Plane &plane, const Vector3D &position, const Vector3D &momentum, double charge, const PropagationDirection propDir=alongMomentum)
std::pair< bool, double >	operator() (const Plane &plane, const GlobalPoint &position, const GlobalVector &momentum, double charge, const PropagationDirection propDir=alongMomentum)
	PathToPlane2Order (const RKLocalFieldProvider &fld, const Frame *fieldFrame)

Private Attributes
const RKLocalFieldProvider &	theField
const Frame *	theFieldFrame

Detailed Description

Definition at line 21 of file PathToPlane2Order.h.

Member Typedef Documentation

typedef GloballyPositioned<Scalar> PathToPlane2Order::Frame

Definition at line 26 of file PathToPlane2Order.h.

typedef Plane::Scalar PathToPlane2Order::Scalar

Definition at line 24 of file PathToPlane2Order.h.

typedef Basic3DVector<Scalar> PathToPlane2Order::Vector3D

Definition at line 25 of file PathToPlane2Order.h.

Constructor & Destructor Documentation

PathToPlane2Order::PathToPlane2Order ( const RKLocalFieldProvider &  fld, const Frame *  fieldFrame  )

inline

Definition at line 28 of file PathToPlane2Order.h.

References alongMomentum, ALCARECOTkAlJpsiMuMu_cff::charge, and position.

                                                                                 : 
      theField(fld), theFieldFrame(fieldFrame) {}

Member Function Documentation

std::pair< bool, double > PathToPlane2Order::operator()	(	const Plane &	plane,
		const Vector3D &	position,
		const Vector3D &	momentum,
		double	charge,
		const PropagationDirection	propDir = alongMomentum
	)

the position and momentum are local in the FieldFrame; the plane is in the global frame

Definition at line 9 of file PathToPlane2Order.cc.

References TtFullHadDaughter::B, PV3DBase< T, PVType, FrameType >::basicVector(), Vector3DBase< T, FrameTag >::cross(), PixelRecoUtilities::curvature(), RKLocalFieldProvider::inTesla(), gen::k, PV3DBase< T, PVType, FrameType >::mag(), Basic3DVector< T >::mag(), PV3DBase< T, PVType, FrameType >::perp(), theField, theFieldFrame, GloballyPositioned< T >::toGlobal(), GloballyPositioned< T >::toLocal(), FrameChanger::transformPlane(), Vector3DBase< T, FrameTag >::unit(), Basic3DVector< T >::unit(), Basic3DVector< T >::x(), Basic3DVector< T >::y(), and Basic3DVector< T >::z().

{
  // access to the field in field frame local coordinates
    RKLocalFieldProvider::Vector B = theField.inTesla( pos.x(), pos.y(), pos.z());

    // Frame::GlobalVector localZ = Frame::GlobalVector( B.unit()); // local Z along field
    // transform field axis to global frame
    Frame::GlobalVector localZ = theFieldFrame->toGlobal( Frame::LocalVector( B.unit())); // local Z along field

    Frame::GlobalVector localY = localZ.cross( Frame::GlobalVector( 1,0,0));
    if (localY.mag() < 0.1) {
    localY = localZ.cross( Frame::GlobalVector(0,1,0)).unit();
    }
    else {
    localY = localY.unit();
    }
    Frame::GlobalVector localX = localY.cross(localZ);


    Frame::PositionType fpos( theFieldFrame->toGlobal( Frame::LocalPoint(pos)));
    Frame::RotationType frot( localX, localY, localZ);
    // frame in which the field is along Z
    Frame frame( fpos, frot);
    
    //    cout << "PathToPlane2Order frame " << frame.position() << endl << frame.rotation() << endl;
    
    // transform the position and direction to that frame
    Frame::LocalPoint localPos = frame.toLocal( fpos); // same as LocalPoint(0,0,0)

    //transform momentum from field frame to new frame via global frame
    Frame::GlobalVector gmom( theFieldFrame->toGlobal( Frame::LocalVector(momentum)));
    Frame::LocalVector localMom = frame.toLocal( gmom); 

    // transform the plane to the same frame
    Plane localPlane =  FrameChanger::transformPlane( plane, frame);
/*
     cout << "PathToPlane2Order input plane       " << plane.position() << endl 
     << plane.rotation() << endl;
     cout << "PathToPlane2Order transformed plane " << localPlane->position() << endl 
     << localPlane->rotation() << endl;
*/
    double k = 2.99792458e-3;
    double transverseMomentum = localMom.perp();   // transverse to the field
    if (!(transverseMomentum != 0) ) {  // if (!(x!=0)) will trap both 0 and NaN
      //LogDebug("PathToPlane2Order_ZeroMomentum") << "Momentum transverse to the field is zero or Nan (" << transverseMomentum << ")\n";
        return std::pair<bool,double>(false,0);
    }
    double curvature = -k * charge * B.mag() / transverseMomentum;
/*
     cout << "PathToPlane2Order curvature " << curvature << endl;
     cout << "transverseMomentum " << transverseMomentum << endl;
     cout << "B.mag() " << B.mag() << endl;
     cout << "localZ " << localZ << endl;
     cout << "pos      " << pos << endl;
     cout << "momentum " << momentum << endl;
     cout << "localPos " << localPos << endl;
     cout << "localMom " << localMom << endl;
*/
/*
    cout << "PathToPlane2Order: local pos " << localPos << " mom " << localMom 
     << " curvature " << curvature << endl;
    cout << "PathToPlane2Order: local plane pos " << localPlane->position() 
     << " normal " << localPlane->normalVector() << endl;
*/
    HelixArbitraryPlaneCrossing crossing( localPos.basicVector(), localMom.basicVector(), 
                      curvature, propDir);
    std::pair<bool,double> res = crossing.pathLength(localPlane);

    return res;
}

std::pair<bool,double> PathToPlane2Order::operator() ( const Plane &  plane, const GlobalPoint &  position, const GlobalVector &  momentum, double  charge, const PropagationDirection  propDir = alongMomentum  )

inline

Definition at line 39 of file PathToPlane2Order.h.

References PV3DBase< T, PVType, FrameType >::basicVector(), ALCARECOTkAlJpsiMuMu_cff::charge, and GloballyPositioned< T >::toLocal().

                                                                           {
    return operator()( plane, theFieldFrame->toLocal(position).basicVector(), 
               theFieldFrame->toLocal(momentum).basicVector(), charge, propDir);
    }

Member Data Documentation

const RKLocalFieldProvider& PathToPlane2Order::theField

private

Definition at line 50 of file PathToPlane2Order.h.

Referenced by operator()().

const Frame* PathToPlane2Order::theFieldFrame

private

Definition at line 51 of file PathToPlane2Order.h.

Referenced by operator()().