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: 2013-04-26 12:39:14 +0200 (Fri, 26 Apr 2013) $ |
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9 | * $Revision: 1099 $ |
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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 | fBitNumber = GetInt("BitNumber", 0); |
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96 | |
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97 | fDeltaR = GetDouble("DeltaR", 0.5); |
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98 | |
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99 | fClassifier->fPTMin = GetDouble("PartonPTMin", 1.0); |
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100 | fClassifier->fEtaMax = GetDouble("PartonEtaMax", 2.5); |
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101 | |
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102 | // read efficiency formulas |
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103 | param = GetParam("EfficiencyFormula"); |
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104 | size = param.GetSize(); |
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105 | |
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106 | fEfficiencyMap.clear(); |
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107 | for(i = 0; i < size/2; ++i) |
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108 | { |
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109 | formula = new DelphesFormula; |
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110 | formula->Compile(param[i*2 + 1].GetString()); |
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111 | |
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112 | fEfficiencyMap[param[i*2].GetInt()] = formula; |
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113 | } |
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114 | |
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115 | // set default efficiency formula |
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116 | itEfficiencyMap = fEfficiencyMap.find(0); |
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117 | if(itEfficiencyMap == fEfficiencyMap.end()) |
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118 | { |
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119 | formula = new DelphesFormula; |
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120 | formula->Compile("0.0"); |
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121 | |
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122 | fEfficiencyMap[0] = formula; |
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123 | } |
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124 | |
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125 | // import input array(s) |
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126 | |
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127 | fPartonInputArray = ImportArray(GetString("PartonInputArray", "Delphes/partons")); |
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128 | fItPartonInputArray = fPartonInputArray->MakeIterator(); |
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129 | |
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130 | fFilter = new ExRootFilter(fPartonInputArray); |
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131 | |
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132 | fJetInputArray = ImportArray(GetString("JetInputArray", "FastJetFinder/jets")); |
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133 | fItJetInputArray = fJetInputArray->MakeIterator(); |
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134 | } |
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135 | |
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136 | //------------------------------------------------------------------------------ |
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137 | |
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138 | void BTagging::Finish() |
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139 | { |
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140 | map< Int_t, DelphesFormula * >::iterator itEfficiencyMap; |
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141 | DelphesFormula *formula; |
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142 | |
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143 | if(fFilter) delete fFilter; |
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144 | if(fItJetInputArray) delete fItJetInputArray; |
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145 | if(fItPartonInputArray) delete fItPartonInputArray; |
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146 | |
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147 | for(itEfficiencyMap = fEfficiencyMap.begin(); itEfficiencyMap != fEfficiencyMap.end(); ++itEfficiencyMap) |
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148 | { |
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149 | formula = itEfficiencyMap->second; |
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150 | if(formula) delete formula; |
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151 | } |
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152 | } |
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153 | |
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154 | //------------------------------------------------------------------------------ |
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155 | |
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156 | void BTagging::Process() |
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157 | { |
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158 | Candidate *jet, *parton; |
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159 | Double_t pt, eta, phi; |
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160 | TObjArray *partonArray; |
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161 | map< Int_t, DelphesFormula * >::iterator itEfficiencyMap; |
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162 | DelphesFormula *formula; |
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163 | Int_t pdgCode, pdgCodeMax; |
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164 | |
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165 | // select quark and gluons |
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166 | fFilter->Reset(); |
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167 | partonArray = fFilter->GetSubArray(fClassifier, 0); |
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168 | |
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169 | if(partonArray == 0) return; |
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170 | |
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171 | TIter itPartonArray(partonArray); |
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172 | |
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173 | // loop over all input jets |
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174 | fItJetInputArray->Reset(); |
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175 | while((jet = static_cast<Candidate*>(fItJetInputArray->Next()))) |
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176 | { |
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177 | const TLorentzVector &jetMomentum = jet->Momentum; |
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178 | pdgCodeMax = -1; |
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179 | eta = jetMomentum.Eta(); |
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180 | phi = jetMomentum.Phi(); |
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181 | pt = jetMomentum.Pt(); |
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182 | |
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183 | // loop over all input partons |
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184 | itPartonArray.Reset(); |
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185 | while((parton = static_cast<Candidate*>(itPartonArray.Next()))) |
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186 | { |
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187 | pdgCode = TMath::Abs(parton->PID); |
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188 | if(pdgCode == 21) pdgCode = 0; |
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189 | if(jetMomentum.DeltaR(parton->Momentum) <= fDeltaR) |
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190 | { |
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191 | if(pdgCodeMax < pdgCode) pdgCodeMax = pdgCode; |
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192 | } |
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193 | } |
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194 | if(pdgCodeMax == 0) pdgCodeMax = 21; |
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195 | if(pdgCodeMax == -1) pdgCodeMax = 0; |
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196 | |
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197 | // find an efficency formula |
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198 | itEfficiencyMap = fEfficiencyMap.find(pdgCodeMax); |
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199 | if(itEfficiencyMap == fEfficiencyMap.end()) |
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200 | { |
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201 | itEfficiencyMap = fEfficiencyMap.find(0); |
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202 | } |
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203 | formula = itEfficiencyMap->second; |
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204 | |
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205 | // apply an efficency formula |
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206 | jet->BTag |= (gRandom->Uniform() <= formula->Eval(pt, eta)) << fBitNumber; |
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207 | } |
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208 | } |
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209 | |
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210 | //------------------------------------------------------------------------------ |
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