FTSFromSimHitFactory Class Reference

#include <FTSFromSimHitFactory.h>

Public Member Functions
FreeTrajectoryState	operator() (const PSimHit &hit, const GeomDetUnit &det, const MagneticField &field) const

Private Member Functions
TrackCharge	charge (int particleId) const

Detailed Description

Produces a FreeTrajectoryState from a SimHit. the FreeTrajectoryState position coinsides with the SimHit position, and direction, momenta and charge are deduced from the SimHit itself, without any access to the SimTrack that produced the SimHit.

Definition at line 17 of file FTSFromSimHitFactory.h.

Member Function Documentation

TrackCharge FTSFromSimHitFactory::charge ( int  particleId ) const

private

Definition at line 17 of file FTSFromSimHitFactory.cc.

References abs.

Referenced by operator()().

{
  if (std::abs( particleId) < 20) {
    // lepton 
    return TrackCharge( (particleId > 0) ? -1 : 1);
  }
  else {
    // only correct for stable mesoms and baryons
    return TrackCharge( (particleId > 0) ? 1 : -1);
  }
}

FreeTrajectoryState FTSFromSimHitFactory::operator()	(	const PSimHit &	hit,
		const GeomDetUnit &	det,
		const MagneticField &	field
	)		const

Definition at line 7 of file FTSFromSimHitFactory.cc.

References charge(), PSimHit::localPosition(), PSimHit::momentumAtEntry(), PSimHit::particleType(), and GeomDet::toGlobal().

{
  GlobalVector momenta = det.toGlobal( hit.momentumAtEntry());
  TrackCharge ch = charge( hit.particleType());
  GlobalTrajectoryParameters param( det.toGlobal( hit.localPosition()), momenta, ch, &field);
  return FreeTrajectoryState( param);
}