Propagate an object (usually a track) to the second muon station. Support for other muon stations will be added on request. More...

#include <HLTriggerOffline/Muon/interface/PropagateToMuon.h>

Public Member Functions
TrajectoryStateOnSurface	extrapolate (const reco::Track &tk) const
	Extrapolate reco::Track to the muon station 2, return an invalid TSOS if it fails.
TrajectoryStateOnSurface	extrapolate (const reco::Candidate &tk) const
	Extrapolate reco::Candidate to the muon station 2, return an invalid TSOS if it fails.
TrajectoryStateOnSurface	extrapolate (const FreeTrajectoryState &state) const
	Extrapolate a FreeTrajectoryState to the muon station 2, return an invalid TSOS if it fails.
void	init (const edm::EventSetup &iSetup)
	Call this method at the beginning of each run, to initialize geometry, magnetic field and propagators.
	PropagateToMuon (const edm::ParameterSet &iConfig)
	~PropagateToMuon ()
Private Types
enum	WhichState { AtVertex, Innermost, Outermost }
enum	WhichTrack { None, TrackerTk, MuonTk, GlobalTk }
Private Member Functions
TrajectoryStateOnSurface	getBestDet (const TrajectoryStateOnSurface &tsos, const DetLayer *station) const
	Get the best TSOS on one of the chambres of this DetLayer, or an invalid TSOS if none match.
FreeTrajectoryState	startingState (const reco::Candidate &reco) const
	Starting state for the propagation.
FreeTrajectoryState	startingState (const reco::Track &tk) const
	Starting state for the propagation.
Private Attributes
const BoundCylinder *	barrelCylinder_
double	barrelHalfLength_
bool	cosmicPropagation_
	for cosmics, some things change: the along-opposite is not in-out, nor the innermost/outermost states are in-out really
const BoundDisk *	endcapDiskNeg_
const BoundDisk *	endcapDiskPos_
std::pair< float, float >	endcapRadii_
edm::ESHandle< MagneticField >	magfield_
edm::ESHandle < MuonDetLayerGeometry >	muonGeometry_
edm::ESHandle< Propagator >	propagator_
edm::ESHandle< Propagator >	propagatorAny_
edm::ESHandle< Propagator >	propagatorOpposite_
bool	useSimpleGeometry_
	Labels for input collections.
WhichState	whichState_
WhichTrack	whichTrack_

Detailed Description

Propagate an object (usually a track) to the second muon station. Support for other muon stations will be added on request.

Author:: Giovanni Petrucciani

Version:

Id:: PropagateToMuon.h,v 1.1 2010/04/15 18:37:17 klukas Exp

Definition at line 30 of file PropagateToMuon.h.

Member Enumeration Documentation

enum PropagateToMuon::WhichState [private]

Enumerator:

AtVertex
Innermost
Outermost

Definition at line 49 of file PropagateToMuon.h.

{ AtVertex, Innermost, Outermost };

enum PropagateToMuon::WhichTrack [private]

Enumerator:

None
TrackerTk
MuonTk
GlobalTk

Definition at line 48 of file PropagateToMuon.h.

{ None, TrackerTk, MuonTk, GlobalTk };

Constructor & Destructor Documentation

PropagateToMuon::PropagateToMuon ( const edm::ParameterSet & iConfig ) [explicit]

Definition at line 18 of file PropagateToMuon.cc.

References AtVertex, cosmicPropagation_, Exception, edm::ParameterSet::getParameter(), GlobalTk, Innermost, MuonTk, None, Outermost, TrackerTk, whichState_, and whichTrack_.

                                                                :
    useSimpleGeometry_(iConfig.getParameter<bool>("useSimpleGeometry")),
    whichTrack_(None), whichState_(AtVertex),
    cosmicPropagation_(iConfig.existsAs<bool>("cosmicPropagationHypothesis") ? iConfig.getParameter<bool>("cosmicPropagationHypothesis") : false)
{
    std::string whichTrack = iConfig.getParameter<std::string>("useTrack");
    if      (whichTrack == "none")    { whichTrack_ = None; }
    else if (whichTrack == "tracker") { whichTrack_ = TrackerTk; }
    else if (whichTrack == "muon")    { whichTrack_ = MuonTk; }
    else if (whichTrack == "global")  { whichTrack_ = GlobalTk; }
    else throw cms::Exception("Configuration") << "Parameter 'useTrack' must be 'none', 'tracker', 'muon', 'global'\n";
    if (whichTrack_ != None) {
        std::string whichState = iConfig.getParameter<std::string>("useState");
        if      (whichState == "atVertex")  { whichState_ = AtVertex; }
        else if (whichState == "innermost") { whichState_ = Innermost; }
        else if (whichState == "outermost") { whichState_ = Outermost; }
        else throw cms::Exception("Configuration") << "Parameter 'useState' must be 'atVertex', 'innermost', 'outermost'\n";
    }
    if (cosmicPropagation_ && (whichTrack_ == None || whichState_ == AtVertex)) {
        throw cms::Exception("Configuration") << "When using 'cosmicPropagationHypothesis' useTrack must not be 'none', and the state must not be 'atVertex'\n";
    }
}

PropagateToMuon::~PropagateToMuon ( )

Definition at line 41 of file PropagateToMuon.cc.

{}

Member Function Documentation

TrajectoryStateOnSurface PropagateToMuon::extrapolate ( const reco::Track & tk ) const [inline]

Extrapolate reco::Track to the muon station 2, return an invalid TSOS if it fails.

Definition at line 39 of file PropagateToMuon.h.

References extrapolate(), and startingState().

Referenced by extrapolate(), and L1MuonMatcherAlgo::extrapolate().

{ return extrapolate(startingState(tk)); }

TrajectoryStateOnSurface PropagateToMuon::extrapolate ( const FreeTrajectoryState & state ) const

Extrapolate a FreeTrajectoryState to the muon station 2, return an invalid TSOS if it fails.

Definition at line 114 of file PropagateToMuon.cc.

References AtVertex, barrelCylinder_, barrelHalfLength_, cosmicPropagation_, Vector3DBase< T, FrameTag >::dot(), endcapDiskNeg_, endcapDiskPos_, endcapRadii_, eta(), PV3DBase< T, PVType, FrameType >::eta(), getBestDet(), TrajectoryStateOnSurface::globalPosition(), TrajectoryStateOnSurface::isValid(), PV3DBase< T, PVType, FrameType >::mag(), FreeTrajectoryState::momentum(), muonGeometry_, PV3DBase< T, PVType, FrameType >::perp(), GloballyPositioned< T >::position(), FreeTrajectoryState::position(), Propagator::propagate(), propagator_, propagatorOpposite_, Cylinder::radius(), rho, useSimpleGeometry_, whichState_, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

                                                                   {
    TrajectoryStateOnSurface final;
    if (start.momentum().mag() == 0) return final;
    double eta = start.momentum().eta();

    const Propagator * propagatorBarrel  = &*propagator_;
    const Propagator * propagatorEndcaps = &*propagator_;

    if (whichState_ != AtVertex) { 
        if (start.position().perp()    > barrelCylinder_->radius())      propagatorBarrel  = &*propagatorOpposite_;
        if (fabs(start.position().z()) > endcapDiskPos_->position().z()) propagatorEndcaps = &*propagatorOpposite_;
    }
    if (cosmicPropagation_) {
        if (start.momentum().dot(GlobalVector(start.position().x(), start.position().y(), start.position().z())) < 0) {
            // must flip the propagations
            propagatorBarrel  = (propagatorBarrel  == &*propagator_ ? &*propagatorOpposite_ : &*propagator_);
            propagatorEndcaps = (propagatorEndcaps == &*propagator_ ? &*propagatorOpposite_ : &*propagator_);
        }
    }

    TrajectoryStateOnSurface tsos = propagatorBarrel->propagate(start, *barrelCylinder_);
    if (tsos.isValid()) {
        if (useSimpleGeometry_) {
            if (fabs(tsos.globalPosition().z()) <= barrelHalfLength_) final = tsos;
        } else {
            final = getBestDet(tsos, muonGeometry_->allDTLayers()[1]);
        }
    } 

    if (!final.isValid()) { 
        tsos = propagatorEndcaps->propagate(start, (eta > 0 ? *endcapDiskPos_ : *endcapDiskNeg_));
        if (tsos.isValid()) {
            if (useSimpleGeometry_) {
                float rho = tsos.globalPosition().perp();
                if ((rho >= endcapRadii_.first) && (rho <= endcapRadii_.second)) final = tsos;
            } else {
                final = getBestDet(tsos, (eta > 0 ? muonGeometry_->forwardCSCLayers()[2] : muonGeometry_->backwardCSCLayers()[2]));
            }
        }
    }
    return final;
}

TrajectoryStateOnSurface PropagateToMuon::extrapolate ( const reco::Candidate & tk ) const [inline]

Extrapolate reco::Candidate to the muon station 2, return an invalid TSOS if it fails.

Definition at line 42 of file PropagateToMuon.h.

References extrapolate(), and startingState().

Referenced by extrapolate().

{ return extrapolate(startingState(tk)); }

TrajectoryStateOnSurface PropagateToMuon::getBestDet	(	const TrajectoryStateOnSurface &	tsos,
		const DetLayer *	station
	)		const `[private]`

Get the best TSOS on one of the chambres of this DetLayer, or an invalid TSOS if none match.

Definition at line 158 of file PropagateToMuon.cc.

References GeometricSearchDet::compatibleDets(), propagatorAny_, and run_regression::ret.

Referenced by extrapolate().

                                                                                             {
    TrajectoryStateOnSurface ret; // start as null
    Chi2MeasurementEstimator estimator(1e10, 3.); // require compatibility at 3 sigma
    std::vector<GeometricSearchDet::DetWithState> dets = layer->compatibleDets(tsos, *propagatorAny_, estimator);
    if (!dets.empty()) {
        ret = dets.front().second;
    }
    return ret;
}

void PropagateToMuon::init ( const edm::EventSetup & iSetup )

Call this method at the beginning of each run, to initialize geometry, magnetic field and propagators.

Definition at line 44 of file PropagateToMuon.cc.

References barrelCylinder_, barrelHalfLength_, BoundSurface::bounds(), endcapDiskNeg_, endcapDiskPos_, endcapRadii_, Exception, edm::EventSetup::get(), BoundDisk::innerRadius(), Bounds::length(), magfield_, muonGeometry_, BoundDisk::outerRadius(), propagator_, propagatorAny_, propagatorOpposite_, and GeometricSearchDet::surface().

Referenced by L1MuonMatcherAlgo::init().

                                                  {
    iSetup.get<IdealMagneticFieldRecord>().get(magfield_);
    iSetup.get<TrackingComponentsRecord>().get("SteppingHelixPropagatorAlong",    propagator_);
    iSetup.get<TrackingComponentsRecord>().get("SteppingHelixPropagatorOpposite", propagatorOpposite_);
    iSetup.get<TrackingComponentsRecord>().get("SteppingHelixPropagatorAny",      propagatorAny_);
    iSetup.get<MuonRecoGeometryRecord>().get(muonGeometry_);

    const DetLayer * dt2 = muonGeometry_->allDTLayers()[1];
    const DetLayer * csc2Pos = muonGeometry_->forwardCSCLayers()[2];
    const DetLayer * csc2Neg = muonGeometry_->backwardCSCLayers()[2];
    barrelCylinder_ = dynamic_cast<const BoundCylinder *>(&dt2->surface());
    endcapDiskPos_  = dynamic_cast<const BoundDisk *>(& csc2Pos->surface());
    endcapDiskNeg_  = dynamic_cast<const BoundDisk *>(& csc2Neg->surface());
    if (barrelCylinder_==0 || endcapDiskPos_==0 || endcapDiskNeg_==0) throw cms::Exception("Geometry") << "Bad muon geometry!?";
    barrelHalfLength_ = barrelCylinder_->bounds().length()/2;;
    endcapRadii_ = std::make_pair(endcapDiskPos_->innerRadius(), endcapDiskPos_->outerRadius());
    //std::cout << "L1MuonMatcher: barrel radius = " << barrelCylinder_->radius() << ", half length = " << barrelHalfLength_ <<
    //             "; endcap Z = " << endcapDiskPos_->position().z() << ", radii = " << endcapRadii_.first << "," << endcapRadii_.second << std::std::endl;
}

FreeTrajectoryState PropagateToMuon::startingState ( const reco::Track & tk ) const [private]

Starting state for the propagation.

Definition at line 92 of file PropagateToMuon.cc.

References AtVertex, cosmicPropagation_, trajectoryStateTransform::initialFreeState(), trajectoryStateTransform::innerFreeState(), Innermost, reco::Track::innerPosition(), magfield_, trajectoryStateTransform::outerFreeState(), Outermost, reco::Track::outerPosition(), edm::ESHandle< T >::product(), and whichState_.

                                                        {
    WhichState state = whichState_;
    if (cosmicPropagation_) { 
        if (whichState_ == Innermost) {
            state = tk.innerPosition().Mag2() <= tk.outerPosition().Mag2()  ? Innermost : Outermost;
        } else if (whichState_ == Outermost) {
            state = tk.innerPosition().Mag2() <= tk.outerPosition().Mag2()  ? Outermost : Innermost;
        }
    }
    switch (state) {
        case Innermost: return trajectoryStateTransform::innerFreeState(  tk, magfield_.product()); 
        case Outermost: return trajectoryStateTransform::outerFreeState(  tk, magfield_.product()); 

        case AtVertex:  
        default:
            return trajectoryStateTransform::initialFreeState(tk, magfield_.product()); 
    }
    
}

FreeTrajectoryState PropagateToMuon::startingState ( const reco::Candidate & reco ) const [private]

Starting state for the propagation.

Definition at line 65 of file PropagateToMuon.cc.

References reco::Candidate::charge(), reco::RecoCandidate::combinedMuon(), Exception, GlobalTk, edm::Ref< C, T, F >::isNull(), magfield_, MuonTk, None, edm::ESHandle< T >::product(), reco::Candidate::px(), reco::Candidate::py(), reco::Candidate::pz(), dt_dqm_sourceclient_common_cff::reco, run_regression::ret, reco::RecoCandidate::standAloneMuon(), reco::RecoCandidate::track(), TrackerTk, reco::Candidate::vx(), reco::Candidate::vy(), reco::Candidate::vz(), and whichTrack_.

Referenced by extrapolate().

                                                              {
    FreeTrajectoryState ret;
    if (whichTrack_ != None) {
        const reco::RecoCandidate *rc = dynamic_cast<const reco::RecoCandidate *>(&reco);
        if (rc == 0) throw cms::Exception("Invalid Data") << "Input object is not a RecoCandidate.\n";
        reco::TrackRef tk;
        switch (whichTrack_) {
            case TrackerTk: tk = rc->track();          break; 
            case MuonTk   : tk = rc->standAloneMuon(); break;
            case GlobalTk : tk = rc->combinedMuon();   break;
            default: break; // just to make gcc happy
        }
        if (tk.isNull()) {
            ret = FreeTrajectoryState();
        } else {
            ret = startingState(*tk);
        }
    } else {
        ret = FreeTrajectoryState(  GlobalPoint( reco.vx(), reco.vy(), reco.vz()),
                                    GlobalVector(reco.px(), reco.py(), reco.pz()),
                                    reco.charge(),
                                    magfield_.product());
    }
    return ret;
}