[1] | 1 | |
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| 2 | /** \class BTagging |
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| 3 | * |
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| 4 | * Determines origin of jet, |
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| 5 | * applies b-tagging efficiency (miss identification rate) formulas |
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| 6 | * and sets b-tagging flags |
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| 7 | * |
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| 8 | * $Date: 2012-12-06 01:10:00 +0100 (Thu, 06 Dec 2012) $ |
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| 9 | * $Revision: 870 $ |
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| 10 | * |
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| 11 | * |
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| 12 | * \author P. Demin - UCL, Louvain-la-Neuve |
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| 13 | * |
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| 14 | */ |
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| 15 | |
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| 16 | #include "modules/BTagging.h" |
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| 17 | |
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| 18 | #include "classes/DelphesClasses.h" |
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| 19 | #include "classes/DelphesFactory.h" |
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| 20 | #include "classes/DelphesFormula.h" |
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| 21 | |
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| 22 | #include "ExRootAnalysis/ExRootResult.h" |
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| 23 | #include "ExRootAnalysis/ExRootFilter.h" |
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| 24 | #include "ExRootAnalysis/ExRootClassifier.h" |
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| 25 | |
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| 26 | #include "TMath.h" |
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| 27 | #include "TString.h" |
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| 28 | #include "TFormula.h" |
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| 29 | #include "TRandom3.h" |
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| 30 | #include "TObjArray.h" |
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| 31 | #include "TDatabasePDG.h" |
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| 32 | #include "TLorentzVector.h" |
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| 33 | |
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| 34 | #include <algorithm> |
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| 35 | #include <stdexcept> |
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| 36 | #include <iostream> |
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| 37 | #include <sstream> |
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| 38 | |
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| 39 | using namespace std; |
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| 40 | |
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| 41 | //------------------------------------------------------------------------------ |
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| 42 | |
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| 43 | class BTaggingPartonClassifier : public ExRootClassifier |
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| 44 | { |
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| 45 | public: |
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| 46 | |
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| 47 | BTaggingPartonClassifier() {} |
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| 48 | |
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| 49 | Int_t GetCategory(TObject *object); |
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| 50 | |
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| 51 | Double_t fEtaMax, fPTMin; |
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| 52 | }; |
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| 53 | |
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| 54 | //------------------------------------------------------------------------------ |
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| 55 | |
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| 56 | Int_t BTaggingPartonClassifier::GetCategory(TObject *object) |
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| 57 | { |
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| 58 | Candidate *parton = static_cast<Candidate*>(object); |
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| 59 | const TLorentzVector &momentum = parton->Momentum; |
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| 60 | Int_t pdgCode; |
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| 61 | |
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| 62 | if(momentum.Pt() <= fPTMin || TMath::Abs(momentum.Eta()) > fEtaMax) return -1; |
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| 63 | |
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| 64 | pdgCode = TMath::Abs(parton->PID); |
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| 65 | if(pdgCode != 21 && pdgCode > 5) return -1; |
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| 66 | |
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| 67 | return 0; |
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| 68 | } |
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| 69 | |
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| 70 | //------------------------------------------------------------------------------ |
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| 71 | |
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| 72 | BTagging::BTagging() : |
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| 73 | fClassifier(0), fFilter(0), |
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| 74 | fItPartonInputArray(0), fItJetInputArray(0) |
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| 75 | { |
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| 76 | fClassifier = new BTaggingPartonClassifier; |
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| 77 | } |
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| 78 | |
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| 79 | //------------------------------------------------------------------------------ |
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| 80 | |
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| 81 | BTagging::~BTagging() |
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| 82 | { |
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| 83 | if(fClassifier) delete fClassifier; |
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| 84 | } |
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| 85 | |
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| 86 | //------------------------------------------------------------------------------ |
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| 87 | |
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| 88 | void BTagging::Init() |
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| 89 | { |
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| 90 | map< Int_t, DelphesFormula * >::iterator itEfficiencyMap; |
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| 91 | ExRootConfParam param; |
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| 92 | DelphesFormula *formula; |
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| 93 | Int_t i, size; |
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| 94 | |
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| 95 | fDeltaR = GetDouble("DeltaR", 0.5); |
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| 96 | |
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| 97 | fClassifier->fPTMin = GetDouble("PartonPTMin", 1.0); |
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| 98 | fClassifier->fEtaMax = GetDouble("PartonEtaMax", 2.5); |
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| 99 | |
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| 100 | // read efficiency formulas |
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| 101 | param = GetParam("EfficiencyFormula"); |
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| 102 | size = param.GetSize(); |
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| 103 | |
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| 104 | fEfficiencyMap.clear(); |
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| 105 | for(i = 0; i < size/2; ++i) |
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| 106 | { |
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| 107 | formula = new DelphesFormula; |
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| 108 | formula->Compile(param[i*2 + 1].GetString()); |
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| 109 | |
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| 110 | fEfficiencyMap[param[i*2].GetInt()] = formula; |
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| 111 | } |
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| 112 | |
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| 113 | // set default efficiency formula |
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| 114 | itEfficiencyMap = fEfficiencyMap.find(0); |
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| 115 | if(itEfficiencyMap == fEfficiencyMap.end()) |
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| 116 | { |
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| 117 | formula = new DelphesFormula; |
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| 118 | formula->Compile("0.0"); |
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| 119 | |
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| 120 | fEfficiencyMap[0] = formula; |
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| 121 | } |
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| 122 | |
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| 123 | // import input array(s) |
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| 124 | |
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| 125 | fPartonInputArray = ImportArray(GetString("PartonInputArray", "Delphes/partons")); |
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| 126 | fItPartonInputArray = fPartonInputArray->MakeIterator(); |
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| 127 | |
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| 128 | fFilter = new ExRootFilter(fPartonInputArray); |
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| 129 | |
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| 130 | fJetInputArray = ImportArray(GetString("JetInputArray", "FastJetFinder/jets")); |
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| 131 | fItJetInputArray = fJetInputArray->MakeIterator(); |
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| 132 | } |
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| 133 | |
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| 134 | //------------------------------------------------------------------------------ |
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| 135 | |
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| 136 | void BTagging::Finish() |
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| 137 | { |
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| 138 | map< Int_t, DelphesFormula * >::iterator itEfficiencyMap; |
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| 139 | DelphesFormula *formula; |
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| 140 | |
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| 141 | if(fFilter) delete fFilter; |
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| 142 | if(fItJetInputArray) delete fItJetInputArray; |
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| 143 | if(fItPartonInputArray) delete fItPartonInputArray; |
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| 144 | |
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| 145 | for(itEfficiencyMap = fEfficiencyMap.begin(); itEfficiencyMap != fEfficiencyMap.end(); ++itEfficiencyMap) |
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| 146 | { |
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| 147 | formula = itEfficiencyMap->second; |
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| 148 | if(formula) delete formula; |
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| 149 | } |
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| 150 | } |
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| 151 | |
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| 152 | //------------------------------------------------------------------------------ |
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| 153 | |
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| 154 | void BTagging::Process() |
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| 155 | { |
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| 156 | Candidate *jet, *parton; |
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| 157 | Double_t pt, eta, phi; |
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| 158 | TObjArray *partonArray; |
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| 159 | map< Int_t, DelphesFormula * >::iterator itEfficiencyMap; |
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| 160 | DelphesFormula *formula; |
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| 161 | Int_t pdgCode, pdgCodeMax; |
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| 162 | |
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| 163 | // select quark and gluons |
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| 164 | fFilter->Reset(); |
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| 165 | partonArray = fFilter->GetSubArray(fClassifier, 0); |
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| 166 | |
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| 167 | if(partonArray == 0) return; |
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| 168 | |
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| 169 | TIter itPartonArray(partonArray); |
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| 170 | |
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| 171 | // loop over all input jets |
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| 172 | fItJetInputArray->Reset(); |
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| 173 | while((jet = static_cast<Candidate*>(fItJetInputArray->Next()))) |
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| 174 | { |
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| 175 | const TLorentzVector &jetMomentum = jet->Momentum; |
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| 176 | pdgCodeMax = -1; |
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| 177 | eta = jetMomentum.Eta(); |
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| 178 | phi = jetMomentum.Phi(); |
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| 179 | pt = jetMomentum.Pt(); |
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| 180 | |
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| 181 | // loop over all input partons |
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| 182 | itPartonArray.Reset(); |
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| 183 | while((parton = static_cast<Candidate*>(itPartonArray.Next()))) |
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| 184 | { |
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| 185 | pdgCode = TMath::Abs(parton->PID); |
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| 186 | if(pdgCode == 21) pdgCode = 0; |
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| 187 | if(jetMomentum.DeltaR(parton->Momentum) <= fDeltaR) |
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| 188 | { |
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| 189 | if(pdgCodeMax < pdgCode) pdgCodeMax = pdgCode; |
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| 190 | } |
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| 191 | } |
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| 192 | if(pdgCodeMax == 0) pdgCodeMax = 21; |
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| 193 | if(pdgCodeMax == -1) pdgCodeMax = 0; |
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| 194 | |
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| 195 | // find an efficency formula |
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| 196 | itEfficiencyMap = fEfficiencyMap.find(pdgCodeMax); |
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| 197 | if(itEfficiencyMap == fEfficiencyMap.end()) |
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| 198 | { |
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| 199 | itEfficiencyMap = fEfficiencyMap.find(0); |
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| 200 | } |
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| 201 | formula = itEfficiencyMap->second; |
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| 202 | |
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| 203 | // apply an efficency formula |
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| 204 | jet->BTag = gRandom->Uniform() <= formula->Eval(pt, eta); |
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| 205 | } |
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| 206 | } |
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| 207 | |
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| 208 | //------------------------------------------------------------------------------ |
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