Merge pull request #36797 from michaelwassmer/CMSSW_12_0_0_SmearMETFi…

…x_short_rebased Fix for smeared MET calculation and its uncertainties.
cms-sw · Feb 6, 2022 · 340f6ea · 340f6ea
2 parents 8e4da88 + ff49d87
commit 340f6ea
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Showing 3 changed files with 31 additions and 3 deletions.
diff --git a/DataFormats/PatCandidates/src/MET.cc b/DataFormats/PatCandidates/src/MET.cc
@@ -342,9 +342,9 @@ void MET::setUncShift(double px, double py, double sumEt, METUncertainty shift,
     //changing reference to only get the uncertainty shift and not the smeared one
     // which is performed independently
     shift = (MET::METUncertainty)(METUncertainty::METUncertaintySize + shift + 1);
-    const PackedMETUncertainty &ref = uncertainties_[METUncertainty::NoShift];
+    const PackedMETUncertainty &ref = corrections_[METCorrectionType::Smear];
     uncertainties_[shift].set(
-        px + ref.dpx() - this->px(), py + ref.dpy() - this->py(), sumEt + ref.dsumEt() - this->sumEt());
+        px - ref.dpx() - this->px(), py - ref.dpy() - this->py(), sumEt - ref.dsumEt() - this->sumEt());
   } else
     uncertainties_[shift].set(px - this->px(), py - this->py(), sumEt - this->sumEt());
 }

diff --git a/JetMETCorrections/Type1MET/interface/PFJetMETcorrInputProducerT.h b/JetMETCorrections/Type1MET/interface/PFJetMETcorrInputProducerT.h
@@ -61,6 +61,16 @@ namespace PFJetMETcorrInputProducer_namespace {
     reco::Candidate::LorentzVector operator()(const T& jet) const { return jet.p4(); }
   };
 
+  // functor to retrieve additional scales of jets
+  // general template just returns 1 because only pat::Jet keeps track of the scales
+  // specialized template for pat::Jet returns combined factor of additional scales
+  template <typename T>
+  class AdditionalScalesT {
+  public:
+    AdditionalScalesT() {}
+    float operator()(const T& jet) const { return 1.0; }
+  };
+
 }  // namespace PFJetMETcorrInputProducer_namespace
 
 template <typename T, typename Textractor>
@@ -196,6 +206,9 @@ class PFJetMETcorrInputProducerT : public edm::stream::EDProducer<> {
         corrJetP4 = jetCorrExtractor_(jet, jetCorrLabel_.label(), jetCorrEtaMax_, &rawJetP4);
       else
         corrJetP4 = jetCorrExtractor_(jet, jetCorr.product(), jetCorrEtaMax_, &rawJetP4);
+      // retrieve additional jet energy scales in case of pat::Jets (done via specialized template defined for pat::Jets) and apply them
+      const static PFJetMETcorrInputProducer_namespace::AdditionalScalesT<T> additionalScales{};
+      corrJetP4 *= additionalScales(jet);
 
       if (corrJetP4.pt() > type1JetPtThreshold_) {
         reco::Candidate::LorentzVector rawJetP4offsetCorr = rawJetP4;

diff --git a/PhysicsTools/PatUtils/plugins/PATPFJetMETcorrInputProducer.cc b/PhysicsTools/PatUtils/plugins/PATPFJetMETcorrInputProducer.cc
@@ -22,11 +22,26 @@ namespace PFJetMETcorrInputProducer_namespace {
     RawJetExtractorT() {}
     reco::Candidate::LorentzVector operator()(const pat::Jet& jet) const {
       if (jet.jecSetsAvailable())
-        return jet.correctedP4("Uncorrected");
+        return jet.correctedP4(0);
       else
         return jet.p4();
     }
   };
+
+  // template specialization for pat::Jets
+  // retrieve combined factor of additional scales applied to the jets
+  // otherwise just return 1
+  template <>
+  class AdditionalScalesT<pat::Jet> {
+  public:
+    AdditionalScalesT() {}
+    float operator()(const pat::Jet& jet) const {
+      if (jet.jecSetsAvailable()) {
+        return jet.jecFactor("Uncorrected") / jet.jecFactor(0);
+      } else
+        return 1.0;
+    }
+  };
 }  // namespace PFJetMETcorrInputProducer_namespace
 
 typedef PFJetMETcorrInputProducerT<pat::Jet, PATJetCorrExtractor> PATPFJetMETcorrInputProducer;