#include <CurvilinearTrajectoryParameters.h>

Public Member Functions
TrackCharge	charge () const
	access to the charge More...

	CurvilinearTrajectoryParameters ()
	default constructor More...

	CurvilinearTrajectoryParameters (const AlgebraicVector5 &v, bool charged=true)

	CurvilinearTrajectoryParameters (const GlobalPoint &aX, const GlobalVector &aP, TrackCharge aCharge)

	CurvilinearTrajectoryParameters (double aQbp, double alambda, double aphi, double axT, double ayT, bool charged=true)

double	lambda () const

double	phi () const

double	Qbp () const

double	signedInverseMomentum () const
	access to the Signed Inverse momentum q/p (zero for neutrals) More...

bool	updateP (double dP)

AlgebraicVector5	vector () const

double	xT () const

double	yT () const

Private Attributes
double	thelambda

double	thephi

double	theQbp

double	thexT

double	theyT

Detailed Description

Class providing access to a set of relevant parameters of a trajectory in a Curvilinear frame. The set consists of the following paramters: \ q/p: charged particles: charge(plus or minus one) divided by magnitude of momentum neutral particles: inverse magnitude of momentum lambda: the helix dip angle (pi/2 minus theta(polar angle)), defined in the global frame phi: the angle of inclination with the global x-axis in the transverse (global xy) plane xT: transverse position in the global xy plane and it points left when looking into the direction of the track yT: transverse position that forms a right-handed frame with xT and zT

Note that the frame is tangent to the track at the point of definition, with Z_T parallel to the track

Definition at line 23 of file CurvilinearTrajectoryParameters.h.

Constructor & Destructor Documentation

◆ CurvilinearTrajectoryParameters() [1/4]

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters ( )

inline

default constructor

Definition at line 27 of file CurvilinearTrajectoryParameters.h.

27 {}

◆ CurvilinearTrajectoryParameters() [2/4]

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	const AlgebraicVector5 &	v,
		bool	charged = `true`
	)

inline

Constructor from vector of parameters Expects a vector of parameters as defined above. For charged particles he charge will be determined by\ the sign of the first element. For neutral particles the last argument should be false, in which case the charge of the first element will be neglected.

Definition at line 35 of file CurvilinearTrajectoryParameters.h.

36 : theQbp(charged ? v[0] : 0), thelambda(v[1]), thephi(v[2]), thexT(v[3]), theyT(v[4]) {}

◆ CurvilinearTrajectoryParameters() [3/4]

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	double	aQbp,
		double	alambda,
		double	aphi,
		double	axT,
		double	ayT,
		bool	charged = `true`
	)

inline

Constructor from vector of parameters Expects a vector of parameters as defined above. For charged particles the charge will be determined by the sign of the first element. For neutral particles the last argument should be false, in which case the charge of the first element will be neglected. Constructor from individual curvilinear parameters Expects parameters as defined above.

Definition at line 48 of file CurvilinearTrajectoryParameters.h.

49 : theQbp(charged ? aQbp : 0), thelambda(alambda), thephi(aphi), thexT(axT), theyT(ayT) {}

◆ CurvilinearTrajectoryParameters() [4/4]

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	const GlobalPoint &	aX,
		const GlobalVector &	aP,
		TrackCharge	aCharge
	)

Constructor from a global vector, global point and track charge

Definition at line 4 of file CurvilinearTrajectoryParameters.cc.

                                                                                       {
   theQbp = aCharge / aP.mag();
  
   double pT2 = aP.x() * aP.x() + aP.y() * aP.y();
   double pT = sqrt(pT2);
   thelambda = atan(aP.z() / pT);
   thephi = atan2(aP.y(), aP.x());
   thexT = (-aP.y() * aX.x() + aP.x() * aX.y()) / pT;
   theyT = (-aX.x() * aP.x() * aP.z() - aX.y() * aP.z() * aP.y() + aX.z() * (pT2)) / (aP.mag() * pT);
 }

References PV3DBase< T, PVType, FrameType >::mag(), PVValHelper::pT, HLT_FULL_cff::pT2, mathSSE::sqrt(), thelambda, thephi, theQbp, thexT, theyT, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Member Function Documentation

◆ charge()

TrackCharge CurvilinearTrajectoryParameters::charge ( void ) const

inline

access to the charge

Definition at line 57 of file CurvilinearTrajectoryParameters.h.

57 { return (0 == Qbp()) ? 0 : (Qbp() > 0 ? 1 : -1); }

References Qbp().

◆ lambda()

double CurvilinearTrajectoryParameters::lambda ( ) const

inline

Definition at line 69 of file CurvilinearTrajectoryParameters.h.

69 { return thelambda; }

References thelambda.

◆ phi()

double CurvilinearTrajectoryParameters::phi ( void ) const

inline

Definition at line 70 of file CurvilinearTrajectoryParameters.h.

70 { return thephi; }

References thephi.

Referenced by Particle.Particle::__str__(), and ntupleDataFormat.Track::phiPull().

◆ Qbp()

double CurvilinearTrajectoryParameters::Qbp ( ) const

inline

Definition at line 68 of file CurvilinearTrajectoryParameters.h.

68 { return theQbp; }

References theQbp.

Referenced by charge(), signedInverseMomentum(), and updateP().

◆ signedInverseMomentum()

double CurvilinearTrajectoryParameters::signedInverseMomentum ( ) const

inline

access to the Signed Inverse momentum q/p (zero for neutrals)

Definition at line 60 of file CurvilinearTrajectoryParameters.h.

60 { return Qbp(); }

References Qbp().

◆ updateP()

bool CurvilinearTrajectoryParameters::updateP ( double dP )

Definition at line 17 of file CurvilinearTrajectoryParameters.cc.

                                                        {
   //FIXME. something is very likely to be missing here
   double p = 1. / std::abs(Qbp());
   if ((p += dP) <= 0.)
     return false;
   double newQbp = Qbp() > 0 ? 1. / p : -1. / p;
   theQbp = newQbp;
   return true;
 }