Rivet analyses
Differential cross-sections for W boson and jets in proton-proton collisions at 13 TeV
Experiment: CMS (LHC)
Inspire ID: 1610623
Status: VALIDATED
Authors: - Emanuela Barberis - Apichart Hortiangtham - Kadir Ocalan
References: - DOI:10.1103/PhysRevD.96.072005 - arXiv: 1707.05979 - Expt page: CMS-SMP-16-005
Beams: p+ p+
Beam energies: (6500.0, 6500.0)GeV
Run details: - 13 TeV $pp \to W+jets$.
Differential cross sections for a W boson produced in association with jets are measured in a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV recorded with the CMS detector and corresponding to an integrated luminosity of 2.2 inverse femtobarns. The W bosons are identified through their decay into a muon and a neutrino. The cross sections are reported as functions of jet multiplicity, jet transverse momenta, jet rapidity $|y|$, the scalar sum of jet transverse momenta ($H_T$), and angular correlations between the muon and each jet for different jet multiplicities. The cross sections are measured in the fiducial region defined by a muon with $p_T > 25$ GeV and pseudorapidity $|\eta| < 2.4$, and by a transverse mass between the muon and the missing transverse energy $M_T > 50$ GeV. Jets are reconstructed using the anti-kT algorithm with a distance parameter R = 0.4, and only jets with $p_T > 30$ GeV, $|y| < 2.4$, and a separation of $\Delta R > 0.4$ from the muon are considered. In addition, the differential cross section is measured as a function of the angular distance (DeltaR) between the muon and the closest jet for events with one or more jets, requiring jets with $p_T > 100$ GeV and the leading jet with $p_T > 300$ GeV.
Source code:CMS_2017_I1610623.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/LeptonFinder.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
namespace Rivet {
/// Differential cross-sections for W boson and jets in proton-proton collisions at 13 TeV
class CMS_2017_I1610623 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2017_I1610623);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
LeptonFinder lf(0.1, Cuts::abseta < 2.4 && Cuts::abspid == PID::MUON);
declare(lf, "Leptons");
declare(MissingMom(), "MET");
// Define veto FS
VetoedFinalState vfs;
vfs.addVetoOnThisFinalState(lf);
vfs.addVetoPairId(PID::MUON);
vfs.vetoNeutrinos();
FastJets fastjets(vfs, JetAlg::ANTIKT, 0.4);
declare(fastjets, "Jets");
book(_hist_Mult_exc, "d01-x01-y01");
book(_hist_inc_WJetMult, "d02-x01-y01");
book(_hist_JetPt1j, "d03-x01-y01");
book(_hist_JetPt2j, "d04-x01-y01");
book(_hist_JetPt3j, "d05-x01-y01");
book(_hist_JetPt4j, "d06-x01-y01");
book(_hist_JetRap1j, "d07-x01-y01");
book(_hist_JetRap2j, "d08-x01-y01");
book(_hist_JetRap3j, "d09-x01-y01");
book(_hist_JetRap4j, "d10-x01-y01");
book(_hist_Ht_1j, "d11-x01-y01");
book(_hist_Ht_2j, "d12-x01-y01");
book(_hist_Ht_3j, "d13-x01-y01");
book(_hist_Ht_4j, "d14-x01-y01");
book(_hist_dphij1mu_1j, "d15-x01-y01");
book(_hist_dphij2mu_2j, "d16-x01-y01");
book(_hist_dphij3mu_3j, "d17-x01-y01");
book(_hist_dphij4mu_4j, "d18-x01-y01");
book(_hist_dRmuj_1j, "d19-x01-y01");
}
/// Used for filling inc Njets histo
void _fill(Histo1DPtr& _histJetMult, vector<FourMomentum>& finaljet_list) {
_histJetMult->fill(0);
for (size_t i = 0; i < finaljet_list.size(); ++i) {
if (i == 6) break;
_histJetMult->fill(i + 1); // inclusive multiplicity
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Identify the closest-matching mu+MET to m == mW
const P4& pmiss = apply<MissingMom>(event, "MET").missingMom();
const Particles& mus = apply<LeptonFinder>(event, "Leptons").particles();
const Particles mus_mtfilt = select(mus, [&](const Particle& m) { return mT(m, pmiss) > 50 * GeV; });
const int imfound = closestMatchIndex(mus_mtfilt, pmiss, Kin::mass, 80.4 * GeV);
// Make cuts on the identified mT and lepton
if (imfound < 0) vetoEvent;
const FourMomentum& lepton0 = mus_mtfilt[imfound].momentum();
if (lepton0.abseta() > 2.4 || lepton0.pT() < 25.0 * GeV) vetoEvent;
// Obtain the jets
vector<FourMomentum> finaljet_list, jet100_list;
double HT = 0.0;
const Jets& js = apply<FastJets>(event, "Jets").jetsByPt(Cuts::pT > 30 * GeV && Cuts::absrap < 2.4);
for (const Jet& j : js) {
const double jpt = j.momentum().pT();
if (deltaR(lepton0, j.momentum()) > 0.4) {
if (jpt > 30.0 * GeV) {
finaljet_list.push_back(j.momentum());
HT += j.momentum().pT();
}
if (jpt > 100.0 * GeV) {
jet100_list.push_back(j.momentum());
}
}
}
// Multiplicity plots
_hist_Mult_exc->fill(finaljet_list.size());
_fill(_hist_inc_WJetMult, finaljet_list);
// dRmuj plot.
double mindR(99999);
if (jet100_list.size() >= 1) {
for (unsigned ji = 0; ji < jet100_list.size(); ji++) {
double dr_(9999);
dr_ = fabs(deltaR(lepton0, jet100_list[ji]));
if (dr_ < mindR) {
mindR = dr_;
}
}
if (jet100_list[0].pT() > 300.0 * GeV) {
_hist_dRmuj_1j->fill(mindR);
}
}
if (finaljet_list.size() >= 1) {
_hist_JetPt1j->fill(finaljet_list[0].pT());
_hist_JetRap1j->fill(fabs(finaljet_list[0].rap()));
_hist_Ht_1j->fill(HT);
_hist_dphij1mu_1j->fill(deltaPhi(finaljet_list[0].phi(), lepton0.phi()));
}
if (finaljet_list.size() >= 2) {
_hist_JetPt2j->fill(finaljet_list[1].pT());
_hist_JetRap2j->fill(fabs(finaljet_list[1].rap()));
_hist_Ht_2j->fill(HT);
_hist_dphij2mu_2j->fill(deltaPhi(finaljet_list[1].phi(), lepton0.phi()));
}
if (finaljet_list.size() >= 3) {
_hist_JetPt3j->fill(finaljet_list[2].pT());
_hist_JetRap3j->fill(fabs(finaljet_list[2].rap()));
_hist_Ht_3j->fill(HT);
_hist_dphij3mu_3j->fill(deltaPhi(finaljet_list[2].phi(), lepton0.phi()));
}
if (finaljet_list.size() >= 4) {
_hist_JetPt4j->fill(finaljet_list[3].pT());
_hist_JetRap4j->fill(fabs(finaljet_list[3].rap()));
_hist_Ht_4j->fill(HT);
_hist_dphij4mu_4j->fill(deltaPhi(finaljet_list[3].phi(), lepton0.phi()));
}
}
/// Normalise histograms etc., after the run
void finalize() {
const double crossec = !std::isnan(crossSectionPerEvent()) ? crossSection() : 61526.7 * picobarn;
if (std::isnan(crossSectionPerEvent())) {
MSG_INFO("No valid cross-section given, using NNLO xsec calculated by FEWZ " << crossec / picobarn
<< " pb");
}
scale(_hist_Mult_exc, crossec / picobarn / sumOfWeights());
scale(_hist_inc_WJetMult, crossec / picobarn / sumOfWeights());
scale(_hist_JetPt1j, crossec / picobarn / sumOfWeights());
scale(_hist_JetPt2j, crossec / picobarn / sumOfWeights());
scale(_hist_JetPt3j, crossec / picobarn / sumOfWeights());
scale(_hist_JetPt4j, crossec / picobarn / sumOfWeights());
scale(_hist_JetRap1j, crossec / picobarn / sumOfWeights());
scale(_hist_JetRap2j, crossec / picobarn / sumOfWeights());
scale(_hist_JetRap3j, crossec / picobarn / sumOfWeights());
scale(_hist_JetRap4j, crossec / picobarn / sumOfWeights());
scale(_hist_Ht_1j, crossec / picobarn / sumOfWeights());
scale(_hist_Ht_2j, crossec / picobarn / sumOfWeights());
scale(_hist_Ht_3j, crossec / picobarn / sumOfWeights());
scale(_hist_Ht_4j, crossec / picobarn / sumOfWeights());
scale(_hist_dphij1mu_1j, crossec / picobarn / sumOfWeights());
scale(_hist_dphij2mu_2j, crossec / picobarn / sumOfWeights());
scale(_hist_dphij3mu_3j, crossec / picobarn / sumOfWeights());
scale(_hist_dphij4mu_4j, crossec / picobarn / sumOfWeights());
scale(_hist_dRmuj_1j, crossec / picobarn / sumOfWeights());
}
/// @}
private:
/// @name Histograms
/// @{
Histo1DPtr _hist_Mult_exc;
Histo1DPtr _hist_inc_WJetMult;
Histo1DPtr _hist_JetPt1j;
Histo1DPtr _hist_JetPt2j;
Histo1DPtr _hist_JetPt3j;
Histo1DPtr _hist_JetPt4j;
Histo1DPtr _hist_JetRap1j;
Histo1DPtr _hist_JetRap2j;
Histo1DPtr _hist_JetRap3j;
Histo1DPtr _hist_JetRap4j;
Histo1DPtr _hist_Ht_1j;
Histo1DPtr _hist_Ht_2j;
Histo1DPtr _hist_Ht_3j;
Histo1DPtr _hist_Ht_4j;
Histo1DPtr _hist_dphij1mu_1j;
Histo1DPtr _hist_dphij2mu_2j;
Histo1DPtr _hist_dphij3mu_3j;
Histo1DPtr _hist_dphij4mu_4j;
Histo1DPtr _hist_dRmuj_1j;
/// @}
};
RIVET_DECLARE_PLUGIN(CMS_2017_I1610623);
}