btau/plugins/HLTDisplacedmumuVtxProducer.cc

0001 #include <iostream>
0002
0003 #include "FWCore/Framework/interface/ESHandle.h"
0004 #include "FWCore/MessageLogger/interface/MessageLogger.h"
0005 #include "FWCore/ParameterSet/interface/ConfigurationDescriptions.h"
0006 #include "DataFormats/Candidate/interface/CandidateFwd.h"
0007 #include "DataFormats/RecoCandidate/interface/RecoCandidate.h"
0008 #include "DataFormats/RecoCandidate/interface/RecoChargedCandidate.h"
0009 #include "DataFormats/RecoCandidate/interface/RecoChargedCandidateFwd.h"
0010 #include "DataFormats/Candidate/interface/Candidate.h"
0011 #include "DataFormats/HLTReco/interface/TriggerFilterObjectWithRefs.h"
0012 #include "DataFormats/HLTReco/interface/TriggerRefsCollections.h"
0013 #include "DataFormats/TrackReco/interface/TrackFwd.h"
0014 #include "DataFormats/TrackReco/interface/Track.h"
0015 #include "DataFormats/VertexReco/interface/Vertex.h"
0016 #include "DataFormats/VertexReco/interface/VertexFwd.h"
0017 #include "DataFormats/Common/interface/RefToBase.h"
0018 #include "RecoVertex/KalmanVertexFit/interface/KalmanVertexFitter.h"
0019 #include "RecoVertex/VertexPrimitives/interface/TransientVertex.h"
0020 #include "HLTDisplacedmumuVtxProducer.h"
0021
0022 using namespace edm;
0023 using namespace reco;
0024 using namespace std;
0025 using namespace trigger;
0026 //
0027 // constructors and destructor
0028 //
0029 HLTDisplacedmumuVtxProducer::HLTDisplacedmumuVtxProducer(const edm::ParameterSet& iConfig)
0030     : transientTrackRecordToken_(esConsumes(edm::ESInputTag("", "TransientTrackBuilder"))),
0031       srcTag_(iConfig.getParameter<edm::InputTag>("Src")),
0032       srcToken_(consumes<reco::RecoChargedCandidateCollection>(srcTag_)),
0033       previousCandTag_(iConfig.getParameter<edm::InputTag>("PreviousCandTag")),
0034       previousCandToken_(consumes<trigger::TriggerFilterObjectWithRefs>(previousCandTag_)),
0035       matchToPrevious_(iConfig.getParameter<bool>("matchToPrevious")),
0036       maxEta_(iConfig.getParameter<double>("MaxEta")),
0037       minPt_(iConfig.getParameter<double>("MinPt")),
0038       minPtPair_(iConfig.getParameter<double>("MinPtPair")),
0039       minInvMass_(iConfig.getParameter<double>("MinInvMass")),
0040       maxInvMass_(iConfig.getParameter<double>("MaxInvMass")),
0041       chargeOpt_(iConfig.getParameter<int>("ChargeOpt")) {
0042   produces<VertexCollection>();
0043 }
0044
0045 HLTDisplacedmumuVtxProducer::~HLTDisplacedmumuVtxProducer() = default;
0046
0047 void HLTDisplacedmumuVtxProducer::fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
0048   edm::ParameterSetDescription desc;
0049   desc.add<edm::InputTag>("Src", edm::InputTag("hltL3MuonCandidates"));
0050   desc.add<edm::InputTag>("PreviousCandTag", edm::InputTag(""));
0051   desc.add<bool>("matchToPrevious", true);
0052   desc.add<double>("MaxEta", 2.5);
0053   desc.add<double>("MinPt", 0.0);
0054   desc.add<double>("MinPtPair", 0.0);
0055   desc.add<double>("MinInvMass", 1.0);
0056   desc.add<double>("MaxInvMass", 20.0);
0057   desc.add<int>("ChargeOpt", -1);
0058   descriptions.add("hltDisplacedmumuVtxProducer", desc);
0059 }
0060
0061 // ------------ method called on each new Event  ------------
0062 void HLTDisplacedmumuVtxProducer::produce(edm::StreamID, edm::Event& iEvent, const edm::EventSetup& iSetup) const {
0063   double const MuMass = 0.106;
0064   double const MuMass2 = MuMass * MuMass;
0065
0066   // get hold of muon trks
0067   Handle<RecoChargedCandidateCollection> mucands;
0068   iEvent.getByToken(srcToken_, mucands);
0069
0070   // get the transient track builder
0071   auto const& theB = iSetup.getHandle(transientTrackRecordToken_);
0072
0073   std::unique_ptr<VertexCollection> vertexCollection(new VertexCollection());
0074
0075   // look at all mucands,  check cuts and make vertices
0076   double e1, e2;
0077   Particle::LorentzVector p, p1, p2;
0078
0079   RecoChargedCandidateCollection::const_iterator cand1;
0080   RecoChargedCandidateCollection::const_iterator cand2;
0081
0082   // get the objects passing the previous filter
0083   Handle<TriggerFilterObjectWithRefs> previousCands;
0084   if (matchToPrevious_)
0085     iEvent.getByToken(previousCandToken_, previousCands);
0086
0087   vector<RecoChargedCandidateRef> vPrevCands;
0088   if (matchToPrevious_)
0089     previousCands->getObjects(TriggerMuon, vPrevCands);
0090
0091   for (cand1 = mucands->begin(); cand1 != mucands->end(); cand1++) {
0092     TrackRef tk1 = cand1->get<TrackRef>();
0093     LogDebug("HLTDisplacedMumuFilter") << " 1st muon in loop: q*pt= " << cand1->charge() * cand1->pt()
0094                                        << ", eta= " << cand1->eta() << ", hits= " << tk1->numberOfValidHits();
0095
0096     //first check if this muon passed the previous filter
0097     if (matchToPrevious_ && !checkPreviousCand(tk1, vPrevCands))
0098       continue;
0099
0100     // cuts
0101     if (fabs(cand1->eta()) > maxEta_)
0102       continue;
0103     if (cand1->pt() < minPt_)
0104       continue;
0105
0106     cand2 = cand1;
0107     cand2++;
0108     for (; cand2 != mucands->end(); cand2++) {
0109       TrackRef tk2 = cand2->get<TrackRef>();
0110
0111       // eta cut
0112       LogDebug("HLTDisplacedmumuVtxProducer")
0113           << " 2nd muon in loop: q*pt= " << cand2->charge() * cand2->pt() << ", eta= " << cand2->eta()
0114           << ", hits= " << tk2->numberOfValidHits() << ", d0= " << tk2->d0();
0115       //first check if this muon passed the previous filter
0116       if (matchToPrevious_ && !checkPreviousCand(tk2, vPrevCands))
0117         continue;
0118
0119       // cuts
0120       if (fabs(cand2->eta()) > maxEta_)
0121         continue;
0122       if (cand2->pt() < minPt_)
0123         continue;
0124
0125       // opposite sign or same sign
0126       if (chargeOpt_ < 0) {
0127         if (cand1->charge() * cand2->charge() > 0)
0128           continue;
0129       } else if (chargeOpt_ > 0) {
0130         if (cand1->charge() * cand2->charge() < 0)
0131           continue;
0132       }
0133
0134       // Combined dimuon system
0135       e1 = sqrt(cand1->momentum().Mag2() + MuMass2);
0136       e2 = sqrt(cand2->momentum().Mag2() + MuMass2);
0137       p1 = Particle::LorentzVector(cand1->px(), cand1->py(), cand1->pz(), e1);
0138       p2 = Particle::LorentzVector(cand2->px(), cand2->py(), cand2->pz(), e2);
0139       p = p1 + p2;
0140
0141       if (p.pt() < minPtPair_)
0142         continue;
0143
0144       double invmass = abs(p.mass());
0145       LogDebug("HLTDisplacedMumuFilter") << " ... 1-2 invmass= " << invmass;
0146
0147       if (invmass < minInvMass_)
0148         continue;
0149       if (invmass > maxInvMass_)
0150         continue;
0151
0152       // do the vertex fit
0153       vector<TransientTrack> t_tks;
0154       TransientTrack ttkp1 = (*theB).build(&tk1);
0155       TransientTrack ttkp2 = (*theB).build(&tk2);
0156       t_tks.push_back(ttkp1);
0157       t_tks.push_back(ttkp2);
0158
0159       if (t_tks.size() != 2)
0160         continue;
0161
0162       KalmanVertexFitter kvf;
0163       TransientVertex tv = kvf.vertex(t_tks);
0164
0165       if (!tv.isValid())
0166         continue;
0167
0168       Vertex vertex = tv;
0169
0170       // put vertex in the event
0171       vertexCollection->push_back(vertex);
0172     }
0173   }
0174   iEvent.put(std::move(vertexCollection));
0175 }
0176
0177 bool HLTDisplacedmumuVtxProducer::checkPreviousCand(const TrackRef& trackref,
0178                                                     const vector<RecoChargedCandidateRef>& refVect) const {
0179   bool ok = false;
0180   for (auto& i : refVect) {
0181     if (i->get<TrackRef>() == trackref) {
0182       ok = true;
0183       break;
0184     }
0185   }
0186   return ok;
0187 }