#include <TSCBLBuilderWithPropagator.h>

Inheritance diagram for TSCBLBuilderWithPropagator:

Public Member Functions
TrajectoryStateClosestToBeamLine	operator() (const FTS &originalFTS, const reco::BeamSpot &beamSpot) const override

	TSCBLBuilderWithPropagator (const MagneticField *field)
	constructor with default geometrical propagator More...

	TSCBLBuilderWithPropagator (const Propagator &u)
	constructor with user-supplied propagator More...

	~TSCBLBuilderWithPropagator () override

Public Member Functions inherited from TrajectoryStateClosestToBeamLineBuilder
virtual	~TrajectoryStateClosestToBeamLineBuilder ()=default

Private Attributes
DeepCopyPointerByClone< Propagator >	thePropagator

Additional Inherited Members
Public Types inherited from TrajectoryStateClosestToBeamLineBuilder
typedef FreeTrajectoryState	FTS

Detailed Description

This class builds a TrajectoryStateClosestToBeamLine given an original FreeTrajectoryState. This new state is then defined at the point of closest approach to the beam line. It is to be used when a specific propagator has to be used.

Definition at line 16 of file TSCBLBuilderWithPropagator.h.

Constructor & Destructor Documentation

◆ TSCBLBuilderWithPropagator() [1/2]

TSCBLBuilderWithPropagator::TSCBLBuilderWithPropagator ( const MagneticField * field )

constructor with default geometrical propagator

Definition at line 8 of file TSCBLBuilderWithPropagator.cc.

9 : thePropagator(new AnalyticalPropagator(field, anyDirection)) {}

◆ TSCBLBuilderWithPropagator() [2/2]

TSCBLBuilderWithPropagator::TSCBLBuilderWithPropagator ( const Propagator & u )

constructor with user-supplied propagator

Definition at line 11 of file TSCBLBuilderWithPropagator.cc.

                                                                           : thePropagator(u.clone()) {
   thePropagator->setPropagationDirection(anyDirection);
 }

References anyDirection, Propagator::setPropagationDirection(), and thePropagator.

◆ ~TSCBLBuilderWithPropagator()

TSCBLBuilderWithPropagator::~TSCBLBuilderWithPropagator ( )

inlineoverride

Definition at line 24 of file TSCBLBuilderWithPropagator.h.

24 {};

Member Function Documentation

◆ operator()()

TrajectoryStateClosestToBeamLine TSCBLBuilderWithPropagator::operator()	(	const FTS &	originalFTS,
		const reco::BeamSpot &	beamSpot
	)		const

overridevirtual

Implements TrajectoryStateClosestToBeamLineBuilder.

Definition at line 15 of file TSCBLBuilderWithPropagator.cc.

                                                                                                             {
   GlobalPoint bspos(beamSpot.position().x(), beamSpot.position().y(), beamSpot.position().z());
   GlobalVector bsvec(beamSpot.dxdz(), beamSpot.dydz(), 1.);
   Line bsline(bspos, bsvec);
  
   TrajectoryExtrapolatorToLine tetl;
  
   TrajectoryStateOnSurface tsosfinal = tetl.extrapolate(originalFTS, bsline, *thePropagator);
  
   if (!tsosfinal.isValid())
     return TrajectoryStateClosestToBeamLine();
  
   //Compute point on beamline of closest approach
   GlobalPoint tp = tsosfinal.globalPosition();  //position of trajectory closest approach
   GlobalVector hyp(
       tp.x() - bspos.x(), tp.y() - bspos.y(), tp.z() - bspos.z());  //difference between traj and beamline reference
   double l = bsline.direction().dot(hyp);                           //length along beamline away from reference point
   GlobalPoint closepoint = bspos + l * bsvec;
  
   //Get the free state and return the TSCBL
   const FreeTrajectoryState theFTS = *tsosfinal.freeState();
   return TrajectoryStateClosestToBeamLine(theFTS, closepoint, beamSpot);
 }