include/JetCorrector.h

#ifndef HZZ2L2NU_INCLUDE_JETCORRECTOR_H_
#define HZZ2L2NU_INCLUDE_JETCORRECTOR_H_

#include <array>
#include <filesystem>
#include <memory>
#include <vector>

#include <TLorentzVector.h>
#include <TTreeReaderValue.h>

#include <Dataset.h>
#include <Options.h>
#include <PhysicsObjects.h>
#include <TabulatedRandomGenerator.h>


// Classes from the JME POG that implement jet corrections are hidden from user
// as in the Pimpl idiom
class FactorizedJetCorrector;
class JetCorrectionUncertainty;

namespace JME {
class JetResolution;
class JetResolutionScaleFactor;
}


class JetCorrector {
 public:
  JetCorrector(Dataset &dataset, Options const &options,
               TabulatedRngEngine &rngEngine);
  ~JetCorrector() noexcept;

  double GetJecFull(TLorentzVector const &rawP4, double area) const;

  double GetJecL1(TLorentzVector const &rawP4, double area) const;

  double GetJecUncFactor(TLorentzVector const &corrP4) const;

  double GetJerFactor(TLorentzVector const &corrP4, GenJet const *genJet,
                      double ptResultion, int rngChannel) const;

  double GetPtResolution(TLorentzVector const &corrP4) const;

  void UpdateIov() const;

 private:
  enum class Syst {
    None,
    JEC,
    JER
  };

  enum class SystDirection {
    Up,
    Down
  };

  using run_t = uint64_t;

  struct IovParams {
    bool Contains(run_t run) const {
      return run >= runRange[0] and run <= runRange[1];
    }

    std::array<run_t, 2> runRange;

    std::vector<std::filesystem::path> jecLevels;
  };

  double ClipFactor(double factor, double pt) const;

  void LoadJec() const;

  void ReadIovParams(YAML::Node const config);

  Syst syst_;

  SystDirection systDirection_;

  std::vector<IovParams> iovs_;

  double minPtClip_;

  mutable IovParams const *currentIov_;

  mutable run_t cachedRun_;

  mutable std::unique_ptr<FactorizedJetCorrector> jetEnergyCorrector_;

  std::unique_ptr<JetCorrectionUncertainty> jecUncProvider_;

  std::unique_ptr<JME::JetResolution> jerProvider_;

  std::unique_ptr<JME::JetResolutionScaleFactor> jerSFProvider_;

  TabulatedRandomGenerator tabulatedRng_;

  mutable TTreeReaderValue<UInt_t> run_;

  mutable TTreeReaderValue<float> rho_;
};

#endif  // HZZ2L2NU_INCLUDE_JETCORRECTOR_H_

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