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Displaced Vertex Finder Algorithm. More...
#include <PFDisplacedVertexHelper.h>
Classes | |
| struct | TracksSelector |
| Tool which store the information for the tracks selection. More... | |
| struct | VertexIdentifier |
| Tool which store the information for the vertex identification. More... | |
Public Member Functions | |
| void | Dump (std::ostream &out=std::cout) const |
| reco::PFDisplacedVertex::VertexType | identifyVertex (const reco::PFDisplacedVertex &v) const |
| Vertex identification tool. | |
| bool | isTrackSelected (const reco::Track &trk, const reco::PFDisplacedVertex::VertexTrackType vertexTrackType) const |
| Select tracks tool. | |
| PFDisplacedVertexHelper () | |
| math::XYZPoint | primaryVertex () const |
| Set Vertex direction using the primary vertex. | |
| void | setPrimaryVertex (edm::Handle< reco::VertexCollection > mainVertexHandle, edm::Handle< reco::BeamSpot > beamSpotHandle) |
| Update the primary vertex information. | |
| void | setTracksSelector (const edm::ParameterSet &ps) |
| Set Tracks selector parameters. | |
| void | setVertexIdentifier (const edm::ParameterSet &ps) |
| Set Vertex identifier parameters. | |
| ~PFDisplacedVertexHelper () | |
Private Member Functions | |
| bool | isKaonMass (const reco::PFDisplacedVertex &v) const |
| int | lambdaCP (const reco::PFDisplacedVertex &v) const |
| Tools used to calculate quantities for vertex identification. | |
Private Attributes | |
| math::XYZPoint | pvtx_ |
| Primary vertex information updated for each event. | |
| TracksSelector | tracksSelector_ |
| VertexIdentifier | vertexIdentifier_ |
Static Private Attributes | |
| static const double | muon_mass2 = 0.106*0.106 |
| static const double | pion_mass2 = 0.0194 |
| Masses2 taken from PDG. | |
| static const double | proton_mass2 = 0.938*0.938 |
Displaced Vertex Finder Algorithm.
Definition at line 17 of file PFDisplacedVertexHelper.h.
| PFDisplacedVertexHelper::PFDisplacedVertexHelper | ( | ) |
Definition at line 19 of file PFDisplacedVertexHelper.cc.
: tracksSelector_(), vertexIdentifier_(), pvtx_(math::XYZPoint(0,0,0)) {}
| PFDisplacedVertexHelper::~PFDisplacedVertexHelper | ( | ) |
Definition at line 24 of file PFDisplacedVertexHelper.cc.
{}
| void PFDisplacedVertexHelper::Dump | ( | std::ostream & | out = std::cout | ) | const |
Definition at line 364 of file PFDisplacedVertexHelper.cc.
References PFDisplacedVertexHelper::TracksSelector::Dump(), PFDisplacedVertexHelper::VertexIdentifier::Dump(), pvtx_, tracksSelector_, and vertexIdentifier_.
Referenced by operator<<().
{
tracksSelector_.Dump();
vertexIdentifier_.Dump();
out << " pvtx_ = " << pvtx_ << std::endl;
}
| reco::PFDisplacedVertex::VertexType PFDisplacedVertexHelper::identifyVertex | ( | const reco::PFDisplacedVertex & | v | ) | const |
Vertex identification tool.
Definition at line 94 of file PFDisplacedVertexHelper.cc.
References reco::PFDisplacedVertex::angle_io(), PFDisplacedVertexHelper::VertexIdentifier::angle_max(), PFDisplacedVertexHelper::VertexIdentifier::angle_V0Conv_max(), cscdqm::ANY, alignmentValidation::c1, DeDxDiscriminatorTools::charge(), sistrip::FAKE, PFDisplacedVertexHelper::VertexIdentifier::identifyVertices(), isKaonMass(), reco::PFDisplacedVertex::isThereMergedTracks(), reco::PFDisplacedVertex::isTherePrimaryTracks(), lambdaCP(), PFDisplacedVertexHelper::VertexIdentifier::logPrimSec_min(), PFDisplacedVertexHelper::VertexIdentifier::looper_eta_max(), PFDisplacedVertexHelper::VertexIdentifier::mConv_max(), PFDisplacedVertexHelper::VertexIdentifier::mK0_max(), PFDisplacedVertexHelper::VertexIdentifier::mK0_min(), PFDisplacedVertexHelper::VertexIdentifier::mNucl_min(), reco::PFDisplacedVertex::nSecondaryTracks(), reco::PFDisplacedVertex::nTracks(), reco::Vertex::originalTrack(), reco::Vertex::position(), reco::PFDisplacedVertex::primaryMomentum(), PFDisplacedVertexHelper::VertexIdentifier::pt_kink_min(), PFDisplacedVertexHelper::VertexIdentifier::pt_min(), reco::Vertex::refittedTracks(), reco::PFDisplacedVertex::secondaryMomentum(), and vertexIdentifier_.
Referenced by PFDisplacedVertexFinder::rejectAndLabelVertex().
{
if (!vertexIdentifier_.identifyVertices()) return PFDisplacedVertex::ANY;
PFDisplacedVertex::M_Hypo massElec = PFDisplacedVertex::M_MASSLESS;
PFDisplacedVertex::M_Hypo massPion = PFDisplacedVertex::M_PION;
math::XYZTLorentzVector mom_ee = v.secondaryMomentum(massElec, true);
math::XYZTLorentzVector mom_pipi = v.secondaryMomentum(massPion, true);
// ===== (1) Identify fake and looper vertices ===== //
double ang = v.angle_io();
double pt_ee = mom_ee.Pt();
double eta_vtx = v.position().eta();
//cout << "Angle = " << ang << endl;
bool bDirectionFake = ang > vertexIdentifier_.angle_max();
bool bLowPt = pt_ee < vertexIdentifier_.pt_min();
bool bLooperEta = fabs(eta_vtx) < vertexIdentifier_.looper_eta_max();
bool isFake = bDirectionFake ||(bLowPt && !bLooperEta);
bool isLooper = !bDirectionFake && bLowPt && bLooperEta;
if (isFake) return PFDisplacedVertex::FAKE;
if (isLooper) return PFDisplacedVertex::LOOPER;
// ===== (2) Identify Decays and Conversions ===== //
int c1 = v.originalTrack(v.refittedTracks()[0])->charge();
int c2 = v.originalTrack(v.refittedTracks()[1])->charge();
double mass_ee = mom_ee.M();
int nTracks = v.nTracks();
int nSecondaryTracks = v.nSecondaryTracks();
bool bPrimaryTracks = v.isTherePrimaryTracks();
bool bMergedTracks = v.isThereMergedTracks();
bool bPair = (nTracks == nSecondaryTracks) && (nTracks == 2);
bool bOpposite = (c1*c2 < -0.1);
bool bDirection = ang < vertexIdentifier_.angle_V0Conv_max();
bool bConvMass = mass_ee < vertexIdentifier_.mConv_max();
bool bV0Conv = bPair && bOpposite && bDirection;
// If the basic configuration of conversions and V0 decays is respected
// pair of secondary track with opposite charge and going in the right direction
// the selection is then based on mass limits
if (bV0Conv){
// == (2.1) Identify Conversions == //
bool isConv = bConvMass;
if (isConv) return PFDisplacedVertex::CONVERSION_LOOSE;
// == (2.2) Identify K0 == //
double mass_pipi = mom_pipi.M();
bool bK0Mass =
mass_pipi < vertexIdentifier_.mK0_max()
&& mass_pipi > vertexIdentifier_.mK0_min();
bool isK0 = bK0Mass;
if (isK0) return PFDisplacedVertex::K0_DECAY;
// == (2.3) Identify Lambda == //
int lambdaKind = lambdaCP(v);
bool isLambda = (lambdaKind == 1);
bool isLambdaBar = (lambdaKind == -1);
if (isLambda) return PFDisplacedVertex::LAMBDA_DECAY;
if (isLambdaBar) return PFDisplacedVertex::LAMBDABAR_DECAY;
}
// == (2.4) Identify K- and K+ ==
bool bK =
(nSecondaryTracks == 1) && bPrimaryTracks && !bMergedTracks
&& !bOpposite;
if(bK){
bool bKMass = isKaonMass(v);
bool isKPlus = bKMass && c1 > 0;
bool isKMinus = bKMass && c1 < 0;
if(isKMinus) return PFDisplacedVertex::KMINUS_DECAY_LOOSE;
if(isKPlus) return PFDisplacedVertex::KPLUS_DECAY_LOOSE;
}
// ===== (3) Identify Nuclears, Kinks and Remaining Fakes ===== //
math::XYZTLorentzVector mom_prim = v.primaryMomentum(massPion, true);
double p_prim = mom_prim.P();
double p_sec = mom_pipi.P();
double pt_prim = mom_prim.Pt();
bool bLog = false;
if (p_prim > 0.05 && p_sec > 0.05) bLog = log10(p_prim/p_sec) > vertexIdentifier_.logPrimSec_min();
bool bPtMin = pt_prim > vertexIdentifier_.pt_kink_min();
// A vertex with at least 3 tracks is considered as high purity nuclear interaction
// the only exception is K- decay into 3 prongs. To be studied.
bool isNuclearHighPurity = nTracks > 2 && mass_ee > vertexIdentifier_.mNucl_min();
bool isFakeHighPurity = nTracks > 2 && mass_ee < vertexIdentifier_.mNucl_min();
// Two secondary tracks with some minimal tracks angular opening are still accepted
// as nuclear interactions
bool isNuclearLowPurity =
(nTracks == nSecondaryTracks)
&& (nTracks == 2)
&& mass_ee > vertexIdentifier_.mNucl_min();
bool isFakeNucl =
(nTracks == nSecondaryTracks)
&& (nTracks == 2)
&& mass_ee < vertexIdentifier_.mNucl_min();
// Kinks: 1 primary + 1 secondary is accepted only if the primary tracks
// has more energy than the secondary and primary have some minimal pT
// to produce a nuclear interaction
bool isNuclearKink =
(nSecondaryTracks == 1) && bPrimaryTracks && !bMergedTracks
&& bLog && bPtMin;
// Here some loopers may hide appearing in Particle Isolation plots. To be studied...
bool isFakeKink =
( (nSecondaryTracks == 1) && bMergedTracks && !bPrimaryTracks )
||
( (nSecondaryTracks == 1) && bPrimaryTracks && !bMergedTracks
&& (!bLog || !bPtMin) );
if (isNuclearHighPurity) return PFDisplacedVertex::NUCL;
if (isNuclearLowPurity) return PFDisplacedVertex::NUCL_LOOSE;
if (isFakeKink || isFakeNucl || isFakeHighPurity) return PFDisplacedVertex::FAKE;
if (isNuclearKink) return PFDisplacedVertex::NUCL_KINK;
return PFDisplacedVertex::ANY;
}
| bool PFDisplacedVertexHelper::isKaonMass | ( | const reco::PFDisplacedVertex & | v | ) | const [private] |
Definition at line 333 of file PFDisplacedVertexHelper.cc.
References PFDisplacedVertexHelper::VertexIdentifier::mK_max(), PFDisplacedVertexHelper::VertexIdentifier::mK_min(), muon_mass2, reco::Vertex::refittedTracks(), mathSSE::sqrt(), reco::PFDisplacedVertex::trackTypes(), and vertexIdentifier_.
Referenced by identifyVertex().
{
math::XYZVector trkInit = v.refittedTracks()[1].momentum(),
trkFinal = v.refittedTracks()[0].momentum();
if (v.trackTypes()[0] == PFDisplacedVertex::T_TO_VERTEX)
trkInit = v.refittedTracks()[0].momentum(),
trkFinal = v.refittedTracks()[1].momentum();
math::XYZVector trkNeutre(trkInit.x()-trkFinal.x(), trkInit.y()-trkFinal.y(),
trkInit.z()-trkFinal.z());
double Ec = sqrt(muon_mass2 + trkFinal.Mag2());
double En = sqrt(0*0 + trkNeutre.Mag2());
math::XYZTLorentzVectorD trkMuNu(trkInit.x(), trkInit.y(), trkInit.z(), Ec+En);
double massMuNu = trkMuNu.M();
bool bKMass =
massMuNu > vertexIdentifier_.mK_min()
&& massMuNu < vertexIdentifier_.mK_max();
return bKMass;
}
| bool PFDisplacedVertexHelper::isTrackSelected | ( | const reco::Track & | trk, |
| const reco::PFDisplacedVertex::VertexTrackType | vertexTrackType | ||
| ) | const |
Select tracks tool.
Definition at line 45 of file PFDisplacedVertexHelper.cc.
References reco::TrackBase::dxy(), PFDisplacedVertexHelper::TracksSelector::dxy_min(), PFDisplacedVertexHelper::TracksSelector::nChi2_max(), PFDisplacedVertexHelper::TracksSelector::nChi2_min(), PFDisplacedVertexHelper::TracksSelector::nHits_min(), reco::TrackBase::normalizedChi2(), PFDisplacedVertexHelper::TracksSelector::nOuterHits_max(), reco::HitPattern::numberOfHits(), reco::TrackBase::numberOfValidHits(), reco::TrackBase::pt(), PFDisplacedVertexHelper::TracksSelector::pt_min(), pvtx_, reco::TrackBase::quality(), PFDisplacedVertexHelper::TracksSelector::quality(), reco::TrackBase::qualityByName(), PFDisplacedVertexHelper::TracksSelector::selectTracks(), reco::PFDisplacedVertex::T_MERGED, reco::PFDisplacedVertex::T_TO_VERTEX, reco::TrackBase::trackerExpectedHitsOuter(), and tracksSelector_.
Referenced by PFDisplacedVertexFinder::fitVertexFromSeed().
{
if (!tracksSelector_.selectTracks()) return true;
bool isGoodTrack = false;
bool isHighPurity = trk.quality( trk.qualityByName(tracksSelector_.quality().data()) );
double nChi2 = trk.normalizedChi2();
double pt = trk.pt();
int nHits = trk.numberOfValidHits();
bool bIsPrimary =
(
(vertexTrackType == reco::PFDisplacedVertex::T_TO_VERTEX)
||
(vertexTrackType == reco::PFDisplacedVertex::T_MERGED)
);
if (bIsPrimary) {
// Primary or merged track selection
isGoodTrack =
( ( nChi2 > tracksSelector_.nChi2_min()
&& nChi2 < tracksSelector_.nChi2_max())
|| isHighPurity )
&& pt > tracksSelector_.pt_min();
} else {
// Secondary tracks selection
int nOuterHits = trk.trackerExpectedHitsOuter().numberOfHits();
double dxy = trk.dxy(pvtx_);
isGoodTrack =
nChi2 < tracksSelector_.nChi2_max()
&& pt > tracksSelector_.pt_min()
&& fabs(dxy) > tracksSelector_.dxy_min()
&& nHits >= tracksSelector_.nHits_min()
&& nOuterHits <= tracksSelector_.nOuterHits_max();
}
return isGoodTrack;
}
| int PFDisplacedVertexHelper::lambdaCP | ( | const reco::PFDisplacedVertex & | v | ) | const [private] |
Tools used to calculate quantities for vertex identification.
Definition at line 246 of file PFDisplacedVertexHelper.cc.
References alignmentValidation::c1, DeDxDiscriminatorTools::charge(), PFDisplacedVertexHelper::VertexIdentifier::mLambda_max(), PFDisplacedVertexHelper::VertexIdentifier::mLambda_min(), reco::Vertex::originalTrack(), reco::TrackBase::p(), pion_mass2, proton_mass2, reco::TrackBase::px(), reco::TrackBase::py(), reco::TrackBase::pz(), reco::Vertex::refittedTracks(), mathSSE::sqrt(), and vertexIdentifier_.
Referenced by identifyVertex().
{
int lambdaCP = 0;
vector <Track> refittedTracks = v.refittedTracks();
math::XYZTLorentzVector totalMomentumDcaRefit_lambda;
math::XYZTLorentzVector totalMomentumDcaRefit_lambdabar;
reco::Track tMomentumDcaRefit_0 = refittedTracks[0];
reco::Track tMomentumDcaRefit_1 = refittedTracks[1];
double mass2_0 = 0, mass2_1 = 0;
int c1 = v.originalTrack(v.refittedTracks()[1])->charge();
// --------------------------- lambda --------------------
if (c1 > 0.1) mass2_0 = pion_mass2, mass2_1 = proton_mass2;
else mass2_0 = proton_mass2, mass2_1 = pion_mass2;
double E = sqrt(tMomentumDcaRefit_0.p()*tMomentumDcaRefit_0.p() + mass2_0);
math::XYZTLorentzVector momentumDcaRefit_0(tMomentumDcaRefit_0.px(), tMomentumDcaRefit_0.py(),
tMomentumDcaRefit_0.pz(), E);
E = sqrt(tMomentumDcaRefit_1.p()*tMomentumDcaRefit_1.p() + mass2_1);
math::XYZTLorentzVector momentumDcaRefit_1(tMomentumDcaRefit_1.px(), tMomentumDcaRefit_1.py(),
tMomentumDcaRefit_1.pz(), E);
totalMomentumDcaRefit_lambda = momentumDcaRefit_0 + momentumDcaRefit_1;
// --------------------------- anti - lambda --------------------
if (c1 > 0.1) mass2_1 = pion_mass2, mass2_0 = proton_mass2;
else mass2_1 = proton_mass2, mass2_0 = pion_mass2;
E = sqrt(tMomentumDcaRefit_0.p()*tMomentumDcaRefit_0.p() + mass2_0);
math::XYZTLorentzVector momentumDcaRefit_01(tMomentumDcaRefit_0.px(), tMomentumDcaRefit_0.py(),
tMomentumDcaRefit_0.pz(), E);
E = sqrt(tMomentumDcaRefit_1.p()*tMomentumDcaRefit_1.p() + mass2_1);
math::XYZTLorentzVector momentumDcaRefit_11(tMomentumDcaRefit_1.px(), tMomentumDcaRefit_1.py(),
tMomentumDcaRefit_1.pz(), E);
totalMomentumDcaRefit_lambdabar = momentumDcaRefit_01 + momentumDcaRefit_11;
double mass_l = totalMomentumDcaRefit_lambda.M();
double mass_lbar = totalMomentumDcaRefit_lambdabar.M();
// cout << "mass_l = " << mass_l << " mass_lbar = " << mass_lbar << endl;
if (
mass_l < mass_lbar
&& mass_l > vertexIdentifier_.mLambda_min()
&& mass_l < vertexIdentifier_.mLambda_max())
lambdaCP = 1;
else if (mass_lbar < mass_l
&& mass_lbar > vertexIdentifier_.mLambda_min()
&& mass_lbar < vertexIdentifier_.mLambda_max())
lambdaCP = -1;
else
lambdaCP = 0;
//cout << "lambdaCP = " << lambdaCP << endl;
return lambdaCP;
}
| math::XYZPoint PFDisplacedVertexHelper::primaryVertex | ( | ) | const [inline] |
Set Vertex direction using the primary vertex.
Definition at line 47 of file PFDisplacedVertexHelper.h.
References pvtx_.
Referenced by PFDisplacedVertexFinder::fitVertexFromSeed().
{ return pvtx_;}
| void PFDisplacedVertexHelper::setPrimaryVertex | ( | edm::Handle< reco::VertexCollection > | mainVertexHandle, |
| edm::Handle< reco::BeamSpot > | beamSpotHandle | ||
| ) |
Update the primary vertex information.
Definition at line 26 of file PFDisplacedVertexHelper.cc.
References SiPixelRawToDigiRegional_cfi::beamSpot, edm::HandleBase::isValid(), and pvtx_.
Referenced by PFDisplacedVertexFinder::setPrimaryVertex().
{
const math::XYZPoint beamSpot = beamSpotHandle.isValid() ?
math::XYZPoint(beamSpotHandle->x0(), beamSpotHandle->y0(), beamSpotHandle->z0()) :
math::XYZPoint(0, 0, 0);
// The primary vertex is taken from the refitted list,
// if does not exist from the average offline beam spot position
// if does not exist (0,0,0) is used
pvtx_ = mainVertexHandle.isValid() ?
math::XYZPoint(mainVertexHandle->begin()->x(),
mainVertexHandle->begin()->y(),
mainVertexHandle->begin()->z()) :
beamSpot;
}
| void PFDisplacedVertexHelper::setTracksSelector | ( | const edm::ParameterSet & | ps | ) | [inline] |
Set Tracks selector parameters.
Definition at line 25 of file PFDisplacedVertexHelper.h.
References tracksSelector_.
Referenced by PFDisplacedVertexFinder::setTracksSelector().
{
tracksSelector_ = TracksSelector(ps);
};
| void PFDisplacedVertexHelper::setVertexIdentifier | ( | const edm::ParameterSet & | ps | ) | [inline] |
Set Vertex identifier parameters.
Definition at line 30 of file PFDisplacedVertexHelper.h.
References vertexIdentifier_.
Referenced by PFDisplacedVertexFinder::setVertexIdentifier().
{
vertexIdentifier_ = VertexIdentifier(ps);
};
const double PFDisplacedVertexHelper::muon_mass2 = 0.106*0.106 [static, private] |
Definition at line 207 of file PFDisplacedVertexHelper.h.
Referenced by isKaonMass().
const double PFDisplacedVertexHelper::pion_mass2 = 0.0194 [static, private] |
Masses2 taken from PDG.
Definition at line 206 of file PFDisplacedVertexHelper.h.
Referenced by lambdaCP().
const double PFDisplacedVertexHelper::proton_mass2 = 0.938*0.938 [static, private] |
Definition at line 208 of file PFDisplacedVertexHelper.h.
Referenced by lambdaCP().
math::XYZPoint PFDisplacedVertexHelper::pvtx_ [private] |
Primary vertex information updated for each event.
Definition at line 203 of file PFDisplacedVertexHelper.h.
Referenced by Dump(), isTrackSelected(), primaryVertex(), and setPrimaryVertex().
Definition at line 200 of file PFDisplacedVertexHelper.h.
Referenced by Dump(), isTrackSelected(), and setTracksSelector().
Definition at line 201 of file PFDisplacedVertexHelper.h.
Referenced by Dump(), identifyVertex(), isKaonMass(), lambdaCP(), and setVertexIdentifier().
1.7.3