Rivet analyses
Parton-level differential top-quark pair production cross-sections in pp collisions at $\sqrt{s} = 8\,\TeV$
Experiment: CMS (LHC)
Inspire ID: 1370682
Status: VALIDATED
Authors: - Jungwan John Goh - Markus Seidel
References: - Eur.Phys.J. C75 (2015) 542
Beams: p+ p+
Beam energies: (4000.0, 4000.0)GeV
Run details: - tt̄ events at $\sqrt{s}= 8\,\TeV$. Top quarks with physical momenta must be present in the event record.
The normalized parton level differential cross section for top quark pair production is measured in pp collisions at a centre-of-mass energy of 8,.
Source
code:CMS_2015_I1370682_PARTON.cc
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/PartonicTops.hh"
namespace Rivet {
class CMS_2015_I1370682_PARTON : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2015_I1370682_PARTON);
/// Book projections and histograms
void init() {
declare(PartonicTops(TopDecay::E_MU, PromptEMuFromTau::NO), "LeptonicPartonTops");
declare(PartonicTops(TopDecay::HADRONIC), "HadronicPartonTops");
book(_hSL_topPt , 15, 1, 1);
book(_hSL_topPtTtbarSys, 16, 1, 1);
book(_hSL_topY , 17, 1, 1);
book(_hSL_ttbarDelPhi , 18, 1, 1);
book(_hSL_topPtLead , 19, 1, 1);
book(_hSL_topPtSubLead , 20, 1, 1);
book(_hSL_ttbarPt , 21, 1, 1);
book(_hSL_ttbarY , 22, 1, 1);
book(_hSL_ttbarMass , 23, 1, 1);
book(_hDL_topPt , 24, 1, 1);
book(_hDL_topPtTtbarSys, 25, 1, 1);
book(_hDL_topY , 26, 1, 1);
book(_hDL_ttbarDelPhi , 27, 1, 1);
book(_hDL_topPtLead , 28, 1, 1);
book(_hDL_topPtSubLead , 29, 1, 1);
book(_hDL_ttbarPt , 30, 1, 1);
book(_hDL_ttbarY , 31, 1, 1);
book(_hDL_ttbarMass , 32, 1, 1);
}
void analyze(const Event& event) {
// Do the analysis only for the ttbar full leptonic or semileptonic channel, without tau decay
const Particles leptonicpartontops = apply<ParticleFinder>(event, "LeptonicPartonTops").particlesByPt();
const Particles hadronicpartontops = apply<ParticleFinder>(event, "HadronicPartonTops").particlesByPt();
const bool isSemilepton = (leptonicpartontops.size() == 1 && hadronicpartontops.size() == 1);
const bool isDilepton = (leptonicpartontops.size() == 2 && hadronicpartontops.size() == 0);
if (!isSemilepton && !isDilepton) vetoEvent;
// Parton level at full phase space
// Fill top quarks defined in the parton level, full phase space
const FourMomentum t1P4 = leptonicpartontops[0];
const FourMomentum t2P4 = isSemilepton ? hadronicpartontops[0] : leptonicpartontops[1];
const double t1Pt = t1P4.pT(), t2Pt = t2P4.pT();
const FourMomentum ttbarP4 = t1P4 + t2P4;
const FourMomentum t1P4AtCM = LorentzTransform::mkFrameTransformFromBeta(ttbarP4.betaVec()).transform(t1P4);
const double dPhi = deltaPhi(t1P4.phi(), t2P4.phi());
if (isSemilepton) {
_hSL_topPt->fill(t1Pt);
_hSL_topPt->fill(t2Pt);
_hSL_topPtTtbarSys->fill(t1P4AtCM.pT());
_hSL_topY->fill(t1P4.rapidity());
_hSL_topY->fill(t2P4.rapidity());
_hSL_ttbarDelPhi->fill(dPhi);
_hSL_topPtLead->fill(std::max(t1Pt, t2Pt));
_hSL_topPtSubLead->fill(std::min(t1Pt, t2Pt));
_hSL_ttbarPt->fill(ttbarP4.pT());
_hSL_ttbarY->fill(ttbarP4.rapidity());
_hSL_ttbarMass->fill(ttbarP4.mass());
} else { // if (isDilepton) {
_hDL_topPt->fill(t1Pt);
_hDL_topPt->fill(t2Pt);
_hDL_topPtTtbarSys->fill(t1P4AtCM.pT());
_hDL_topY->fill(t1P4.rapidity());
_hDL_topY->fill(t2P4.rapidity());
_hDL_ttbarDelPhi->fill(dPhi);
_hDL_topPtLead->fill(std::max(t1Pt, t2Pt));
_hDL_topPtSubLead->fill(std::min(t1Pt, t2Pt));
_hDL_ttbarPt->fill(ttbarP4.pT());
_hDL_ttbarY->fill(ttbarP4.rapidity());
_hDL_ttbarMass->fill(ttbarP4.mass());
}
}
void finalize() {
normalize(_hSL_topPt); normalize(_hSL_topPtTtbarSys); normalize(_hSL_topY);
normalize(_hSL_ttbarDelPhi); normalize(_hSL_topPtLead); normalize(_hSL_topPtSubLead);
normalize(_hSL_ttbarPt); normalize(_hSL_ttbarY); normalize(_hSL_ttbarMass);
normalize(_hDL_topPt); normalize(_hDL_topPtTtbarSys); normalize(_hDL_topY);
normalize(_hDL_ttbarDelPhi); normalize(_hDL_topPtLead); normalize(_hDL_topPtSubLead);
normalize(_hDL_ttbarPt); normalize(_hDL_ttbarY); normalize(_hDL_ttbarMass);
}
private:
/// @name Histograms
/// @{
Histo1DPtr _hSL_topPt, _hSL_topPtTtbarSys, _hSL_topY, _hSL_ttbarDelPhi, _hSL_topPtLead,
_hSL_topPtSubLead, _hSL_ttbarPt, _hSL_ttbarY, _hSL_ttbarMass;
Histo1DPtr _hDL_topPt, _hDL_topPtTtbarSys, _hDL_topY, _hDL_ttbarDelPhi, _hDL_topPtLead,
_hDL_topPtSubLead, _hDL_ttbarPt, _hDL_ttbarY, _hDL_ttbarMass;
/// @}
};
RIVET_DECLARE_PLUGIN(CMS_2015_I1370682_PARTON);
}