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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/DressedLeptons.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "Rivet/Projections/PromptFinalState.hh"
namespace Rivet {
/// @brief Production cross-sections of WZ and same-sign WW with two jets in pp collisions at 13 TeV
class CMS_2020_I1794169 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2020_I1794169);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
_mode = 0;
if ( getOption("LMODE") == "WZ" ) _mode = 1;
// The basic final-state projection:
// all final-state particles within
// the given eta acceptance
const FinalState fs(Cuts::abseta < 4.9);
const FinalState fsjet4p7(Cuts::abseta < 4.7);
// The final-state particles declared above are clustered using FastJet with
// the anti-kT algorithm and a jet-radius parameter 0.4
// muons and neutrinos are excluded from the clustering
FastJets jet4p7fs(fsjet4p7, FastJets::ANTIKT, 0.4);
declare(jet4p7fs, "jets4p7");
// FinalState of prompt photons and bare muons and electrons in the event
PromptFinalState photons(Cuts::abspid == PID::PHOTON);
PromptFinalState bare_leps(Cuts::abspid == PID::MUON || Cuts::abspid == PID::ELECTRON);
bare_leps.acceptTauDecays(false);
// Dress the prompt bare leptons with prompt photons within dR < 0.1,
// and apply some fiducial cuts on the dressed leptons
Cut lepton_cuts = Cuts::abseta < 2.5 && Cuts::pT > 20*GeV;
DressedLeptons dressed_leps(photons, bare_leps, 0.1, lepton_cuts);
declare(dressed_leps, "leptons");
// Missing momentum
declare(MissingMomentum(fs), "MET");
// Book histograms
book(_h_WW_mjj , 9, 1, 1);
book(_h_WW_mll , 11, 1, 1);
book(_h_WW_ptlmax, 13, 1, 1);
book(_h_WZ_mjj , 15, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Retrieve dressed leptons, sorted by pT
Particles leptons = apply<DressedLeptons>(event, "leptons").particles();
// Apply a #leptons requirement
if (leptons.size() <= 1 || leptons.size() >= 4) return;
// Retrieve clustered jets, sorted by pT, with a minimum pT cut
Jets jets50 = apply<FastJets>(event, "jets4p7").jetsByPt(Cuts::pT > 50*GeV);
// Remove all jets within dR < 0.4 of a dressed lepton
idiscardIfAnyDeltaRLess(jets50, leptons, 0.4);
// Apply a njets >= 2 cut
if (jets50.size() < 2) return;
FourMomentum dijetCand = jets50[0].momentum() + jets50[1].momentum();
double deltaEtaJJ = std::abs(jets50[0].eta() - jets50[1].eta());
// Apply a mjj > 500 and detajj > 2.5 cuts
if (dijetCand.mass() <= 500*GeV || deltaEtaJJ <= 2.5) return;
// W+W+ selection
if (leptons.size() == 2 && leptons[0].pid() * leptons[1].pid() > 0 && _mode == 0) {
FourMomentum dilCand = leptons[0].momentum() + leptons[1].momentum();
if (dilCand.mass() > 20*GeV) {
double ptlmax = leptons[0].pt(); double ptlmin = leptons[1].pt();
if (ptlmax < ptlmin) {
ptlmax = leptons[1].pt(); ptlmin = leptons[0].pt();
}
_h_WW_mjj ->fill(min(dijetCand.mass()/GeV, 2999.999));
_h_WW_mll ->fill(min(dilCand.mass()/GeV, 499.999));
_h_WW_ptlmax->fill(min(ptlmax/GeV, 299.999));
}
}
// WZ selection
else if (leptons.size() == 3 && _mode == 1) {
double mllZ = 10000; int iW = -1;
if (leptons[0].pid() * leptons[1].pid() < 0 && leptons[0].abspid() == leptons[1].abspid() &&
fabs((leptons[0].momentum() + leptons[1].momentum()).mass() - 91.1876*GeV) < fabs(mllZ - 91.1876*GeV)) {
mllZ = (leptons[0].momentum() + leptons[1].momentum()).mass(); iW = 2;
}
if (leptons[0].pid() * leptons[2].pid() < 0 && leptons[0].abspid() == leptons[2].abspid() &&
fabs((leptons[0].momentum() + leptons[2].momentum()).mass() - 91.1876*GeV) < fabs(mllZ - 91.1876*GeV)) {
mllZ = (leptons[0].momentum() + leptons[2].momentum()).mass(); iW = 1;
}
if (leptons[1].pid() * leptons[2].pid() < 0 && leptons[1].abspid() == leptons[2].abspid() &&
fabs((leptons[1].momentum() + leptons[2].momentum()).mass() - 91.1876*GeV) < fabs(mllZ - 91.1876*GeV)) {
mllZ = (leptons[1].momentum() + leptons[2].momentum()).mass(); iW = 0;
}
// Plot
if (iW >= 0 && fabs(mllZ - 91.1876*GeV) < 15*GeV) {
_h_WZ_mjj->fill(min(dijetCand.mass()/GeV, 2999.999));
}
}
}
/// @todo Replace with barchart()
void normalizeToSum(Histo1DPtr hist) {
double sum = 0.;
for (size_t i = 0; i < hist->numBins(); ++i) {
sum += hist->bin(i).height();
float width = hist->bin(i).width();
hist->bin(i).scaleW(width != 0 ? width : 1.);
}
if(hist->integral() > 0) scale(hist, 1./hist->integral());
}
/// Normalise histograms etc., after the run
void finalize() {
double norm = (sumOfWeights() != 0) ? crossSection()/femtobarn/sumOfWeights() : 1.0;
scale(_h_WW_mjj , norm);
scale(_h_WW_mll , norm);
scale(_h_WW_ptlmax, norm);
scale(_h_WZ_mjj , norm);
}
//@}
private:
/// Lepton-mode flag
size_t _mode;
/// @name Histograms
/// @{
Histo1DPtr _h_WW_mjj, _h_WW_mll, _h_WW_ptlmax, _h_WZ_mjj;
/// @}
};
RIVET_DECLARE_PLUGIN(CMS_2020_I1794169);
}
|