EWKSystUnc.cc

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#include "FWCore/Framework/interface/EDAnalyzer.h"
#include "FWCore/Utilities/interface/InputTag.h"
#include "DataFormats/HepMCCandidate/interface/GenParticle.h"
#include "DataFormats/HepMCCandidate/interface/GenParticleFwd.h"
#include "TH1.h"

class EWKSystUnc : public edm::EDAnalyzer {
public:
  EWKSystUnc(const edm::ParameterSet& pset);

private:
  void analyze(const edm::Event& event, const edm::EventSetup& setup) override;
  void endJob() override;
  edm::EDGetTokenT<reco::GenParticleCollection> genToken_;
  edm::EDGetTokenT<double> weightsToken_;
  unsigned int nbinsMass_, nbinsPt_, nbinsAng_;
  double massMax_, ptMax_, angMax_;
  double accPtMin_, accMassMin_, accMassMax_, accEtaMin_, accEtaMax_;
  TH1F* h_nZ_;
  TH1F *h_mZMC_, *h_ptZMC_, *h_phiZMC_, *h_thetaZMC_, *h_etaZMC_, *h_rapidityZMC_;
  TH1F *hardpt, *softpt, *hardeta, *softeta;
  TH1F* h_weight_histo;
  bool isMCatNLO_;
  double nAcc_, nAccReW_, nBothMuHasZHasGrandMa_;
  std::string filename_;
};

#include "DataFormats/Candidate/interface/Candidate.h"
#include "DataFormats/Candidate/interface/CandidateFwd.h"
#include "DataFormats/Candidate/interface/CandMatchMap.h"
#include "SimDataFormats/GeneratorProducts/interface/HepMCProduct.h"

#include "HepMC/WeightContainer.h"
#include "HepMC/GenEvent.h"
#include "FWCore/Framework/interface/Event.h"
#include "DataFormats/Common/interface/Handle.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/ServiceRegistry/interface/Service.h"
#include "CommonTools/UtilAlgos/interface/TFileService.h"
#include <cmath>
#include <iostream>
#include <fstream>

using namespace std;
using namespace reco;
using namespace edm;

EWKSystUnc::EWKSystUnc(const ParameterSet& pset)
    : genToken_(consumes<GenParticleCollection>(pset.getParameter<InputTag>("genParticles"))),
      weightsToken_(consumes<double>(pset.getParameter<InputTag>("weights"))),
      nbinsMass_(pset.getUntrackedParameter<unsigned int>("nbinsMass")),
      nbinsPt_(pset.getUntrackedParameter<unsigned int>("nbinsPt")),
      nbinsAng_(pset.getUntrackedParameter<unsigned int>("nbinsAng")),
      massMax_(pset.getUntrackedParameter<double>("massMax")),
      ptMax_(pset.getUntrackedParameter<double>("ptMax")),
      angMax_(pset.getUntrackedParameter<double>("angMax")),
      accPtMin_(pset.getUntrackedParameter<double>("accPtMin")),
      accMassMin_(pset.getUntrackedParameter<double>("accMassMin")),
      accMassMax_(pset.getUntrackedParameter<double>("accMassMax")),
      accEtaMin_(pset.getUntrackedParameter<double>("accEtaMin")),
      accEtaMax_(pset.getUntrackedParameter<double>("accEtaMax")),
      isMCatNLO_(pset.getUntrackedParameter<bool>("isMCatNLO")),
      filename_(pset.getUntrackedParameter<std::string>("outfilename")) {
  cout << ">>> Z Histogrammer constructor" << endl;
  Service<TFileService> fs;

  TFileDirectory ZMCHisto = fs->mkdir("ZMCHisto");
  h_nZ_ = ZMCHisto.make<TH1F>("ZNumber", "number of Z particles", 11, -0.5, 10.5);
  h_weight_histo = ZMCHisto.make<TH1F>("weight_histo", "weight_histo", 20, -10, 10);

  h_mZMC_ = ZMCHisto.make<TH1F>("ZMCMass", "Z MC mass (GeV/c^{2})", nbinsMass_, 0, massMax_);
  h_ptZMC_ = ZMCHisto.make<TH1F>("ZMCPt", "Z MC p_{t} (GeV/c)", nbinsPt_, 0, ptMax_);
  hardpt = ZMCHisto.make<TH1F>("hardpt", "hard muon p_{t} (GeV/c)", nbinsPt_, 0, ptMax_);
  softpt = ZMCHisto.make<TH1F>("softpt", "soft muon p_{t} (GeV/c)", nbinsPt_, 0, ptMax_);

  h_phiZMC_ = ZMCHisto.make<TH1F>("ZMCPhi", "Z MC #phi", nbinsAng_, -angMax_, angMax_);
  h_thetaZMC_ = ZMCHisto.make<TH1F>("ZMCTheta", "Z MC #theta", nbinsAng_, 0, angMax_);
  h_etaZMC_ = ZMCHisto.make<TH1F>("ZMCEta", "Z MC #eta", nbinsAng_, -angMax_, angMax_);
  h_rapidityZMC_ = ZMCHisto.make<TH1F>("ZMCRapidity", "Z MC y", nbinsAng_, -angMax_, angMax_);

  hardeta = ZMCHisto.make<TH1F>("hard muon eta", "hard muon #eta", nbinsAng_, -angMax_, angMax_);
  softeta = ZMCHisto.make<TH1F>("soft muon eta", "soft muon #eta", nbinsAng_, -angMax_, angMax_);
  nAcc_ = 0.;
  nAccReW_ = 0;
  nBothMuHasZHasGrandMa_ = 0;
}

void EWKSystUnc::analyze(const edm::Event& event, const edm::EventSetup& setup) {
  cout << ">>> Z Histogrammer analyze" << endl;

  Handle<GenParticleCollection> gen;
  Handle<double> weights;

  event.getByToken(genToken_, gen);
  event.getByToken(weightsToken_, weights);

  // get weight and fill it to histogram
  double weight = (*weights);

  // protection...
  if (weight > 2. || weight < 0.1) {
    std::cout << "weight  = " << weight << ", something strange...." << std::endl;
    weight = 1;
  }
  h_weight_histo->Fill(weight);

  std::vector<GenParticle> muons;

  for (unsigned int i = 0; i < gen->size(); ++i) {
    const GenParticle& muMC = (*gen)[i];
    // filling only muons coming form Z
    if (abs(muMC.pdgId()) == 13 && muMC.status() == 1 && muMC.numberOfMothers() > 0) {
      if (muMC.mother()->numberOfMothers() > 0) {
        cout << "I'm getting a muon \n"
             << "with "
             << "muMC.numberOfMothers()  " << muMC.numberOfMothers() << "\n the first mother has pdgId "
             << muMC.mother()->pdgId() << "with "
             << "muMC.mother()->numberOfMothers()  " << muMC.mother()->numberOfMothers()
             << "\n the first grandma has pdgId " << muMC.mother()->mother()->pdgId() << endl;
        if (muMC.mother()->mother()->pdgId() == 23)
          muons.push_back(muMC);
      }
    }
  }

  cout << "finally I selected " << muons.size() << " muons" << endl;

  // if there are at least two muons,
  // calculate invarant mass of first two and fill it into histogram

  double inv_mass = 0.0;
  double Zpt_ = 0.0;
  double Zeta_ = 0.0;
  double Ztheta_ = 0.0;
  double Zphi_ = 0.0;
  double Zrapidity_ = 0.0;

  if (muons.size() > 1) {
    if (muons[0].mother()->mother()->pdgId() == 23 && muons[1].mother()->mother()->pdgId() == 23)
      nBothMuHasZHasGrandMa_++;
    math::XYZTLorentzVector tot_momentum(muons[0].p4());
    math::XYZTLorentzVector mom2(muons[1].p4());
    tot_momentum += mom2;
    inv_mass = sqrt(tot_momentum.mass2());
    Zpt_ = tot_momentum.pt();
    Zeta_ = tot_momentum.eta();
    Ztheta_ = tot_momentum.theta();
    Zphi_ = tot_momentum.phi();
    Zrapidity_ = tot_momentum.Rapidity();

    // IMPORTANT: use the weight of the event ...

    double weight_sign = weight;
    //double weight_sign = 1.    ;
    h_mZMC_->Fill(inv_mass, weight_sign);
    h_ptZMC_->Fill(Zpt_, weight_sign);
    h_etaZMC_->Fill(Zeta_, weight_sign);
    h_thetaZMC_->Fill(Ztheta_, weight_sign);
    h_phiZMC_->Fill(Zphi_, weight_sign);
    h_rapidityZMC_->Fill(Zrapidity_, weight_sign);

    double pt1 = muons[0].pt();
    double pt2 = muons[1].pt();
    double eta1 = muons[0].eta();
    double eta2 = muons[1].eta();

    if (pt1 > pt2) {
      hardpt->Fill(pt1, weight_sign);
      softpt->Fill(pt2, weight_sign);
      hardeta->Fill(eta1, weight_sign);
      softeta->Fill(eta2, weight_sign);
    } else {
      hardpt->Fill(pt2, weight_sign);
      softpt->Fill(pt1, weight_sign);
      hardeta->Fill(eta2, weight_sign);
      softeta->Fill(eta1, weight_sign);
    }

    //evaluating the geometric acceptance
    if (pt1 >= accPtMin_ && pt2 >= accPtMin_ && fabs(eta1) >= accEtaMin_ && fabs(eta2) >= accEtaMin_ &&
        fabs(eta1) <= accEtaMax_ && fabs(eta2) <= accEtaMax_ && inv_mass >= accMassMin_ && inv_mass <= accMassMax_) {
      nAcc_++;
      nAccReW_ += weight;
    }
  }
}

void EWKSystUnc::endJob() {
  cout << " number of events accepted :" << nAcc_ << endl;
  cout << " number of events accepted reweigthed :" << nAccReW_ << endl;
  double nev = h_mZMC_->GetEntries();
  double nev_weigthed = h_mZMC_->Integral(0, nbinsMass_ + 1);
  cout << " number of total events :" << nev << endl;
  cout << " number of total weighted events :" << nev_weigthed << endl;
  cout << " number of cases in which BothMuHasZHasGrandMa :" << nBothMuHasZHasGrandMa_ << endl;
  double eff = (double)nAcc_ / (double)h_mZMC_->GetEntries();
  double eff_rew = (double)nAccReW_ / (double)h_mZMC_->Integral(0, nbinsMass_ + 1);
  double err = sqrt(eff * (1. - eff) / (double)h_mZMC_->GetEntries());
  double err_rew = sqrt(eff_rew * (1. - eff_rew) / (double)h_mZMC_->Integral(0, nbinsMass_ + 1));
  cout << " geometric acceptance: " << eff << "+/-" << err << endl;
  cout << " geometric acceptance reweighted: " << eff_rew << "+/-" << err_rew << endl;

  ofstream myfile;
  myfile.open(filename_.c_str(), std::ios::app);
  myfile << eff << " " << eff_rew << " " << nev << " " << nev_weigthed << endl;
  myfile.close();
}
#include "FWCore/Framework/interface/MakerMacros.h"

DEFINE_FWK_MODULE(EWKSystUnc);