Rivet analyses
High jet multiplicity squark and gluino search
Experiment: ATLAS (LHC)
Inspire ID: 1117704
Status: VALIDATED
Authors: - Peter Richardson
References: - Expt page: ATLAS-SUSY-2011-19 - arXiv: 1206.1760
Beams: p+ p+
Beam energies: (3500.0, 3500.0)GeV
Run details: - BSM signal events at 7000 GeV.
Search for SUSY using events with 6 or more jets in association with missing transverse momentum produced in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data sample has a total integrated luminosity of 4.7 fb−1. Distributions in the W and top control regions are not produced, while in addition to the plots from the paper the count of events in the different signal regions is included.
Source
code:ATLAS_2012_I1117704.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
#include "Rivet/Projections/VisibleFinalState.hh"
#include "Rivet/Tools/RivetMT2.hh"
namespace Rivet {
class ATLAS_2012_I1117704 : public Analysis {
public:
/// @name Constructors etc.
/// @{
/// Constructor
ATLAS_2012_I1117704()
: Analysis("ATLAS_2012_I1117704") { }
/// @}
public:
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projection to find the electrons
IdentifiedFinalState elecs(Cuts::abseta < 2.47 && Cuts::pT > 20 * GeV);
elecs.acceptIdPair(PID::ELECTRON);
declare(elecs, "elecs");
// projection to find the muons
IdentifiedFinalState muons(Cuts::abseta < 2.4 && Cuts::pT > 10 * GeV);
muons.acceptIdPair(PID::MUON);
declare(muons, "muons");
// for pTmiss
declare(VisibleFinalState(Cuts::abseta < 4.9), "vfs");
VetoedFinalState vfs;
vfs.addVetoPairId(PID::MUON);
/// Jet finder
declare(FastJets(vfs, JetAlg::ANTIKT, 0.4), "AntiKtJets04");
// all tracks (to do deltaR with leptons)
declare(ChargedFinalState(Cuts::abseta < 3), "cfs");
/// Book histograms
book(_etmiss_HT_7j55, "etmiss_HT_7j55", 8, 0., 16.);
book(_etmiss_HT_8j55, "etmiss_HT_8j55", 8, 0., 16.);
book(_etmiss_HT_9j55, "etmiss_HT_9j55", 8, 0., 16.);
book(_etmiss_HT_6j80, "etmiss_HT_6j80", 8, 0., 16.);
book(_etmiss_HT_7j80, "etmiss_HT_7j80", 8, 0., 16.);
book(_etmiss_HT_8j80, "etmiss_HT_8j80", 8, 0., 16.);
book(_hist_njet55, "hist_njet55", 11, 2.5, 13.5);
book(_hist_njet80, "hist_njet80", 11, 2.5, 13.5);
book(_count_7j55, "count_7j55", 1, 0., 1.);
book(_count_8j55, "count_8j55", 1, 0., 1.);
book(_count_9j55, "count_9j55", 1, 0., 1.);
book(_count_6j80, "count_6j80", 1, 0., 1.);
book(_count_7j80, "count_7j80", 1, 0., 1.);
book(_count_8j80, "count_8j80", 1, 0., 1.);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// get the jet candidates
Jets cand_jets = apply<FastJets>(event, "AntiKtJets04")
.jetsByPt(Cuts::pT > 20.0 * GeV && Cuts::abseta < 2.8);
// candidate muons
Particles cand_mu;
Particles chg_tracks = apply<ChargedFinalState>(event, "cfs").particles();
for (const Particle& mu : apply<IdentifiedFinalState>(event, "muons").particlesByPt()) {
double pTinCone = -mu.pT();
for (const Particle& track : chg_tracks) {
if (deltaR(mu.momentum(), track.momentum()) <= 0.2) pTinCone += track.pT();
}
if (pTinCone < 1.8 * GeV) cand_mu.push_back(mu);
}
// candidate electrons
Particles cand_e = apply<IdentifiedFinalState>(event, "elecs").particlesByPt();
// resolve jet/lepton ambiguity
Jets recon_jets;
for (const Jet& jet : cand_jets) {
// candidates after |eta| < 2.8
if (fabs(jet.eta()) >= 2.8) continue;
bool away_from_e = true;
for (const Particle& e : cand_e) {
if (deltaR(e.momentum(), jet.momentum()) <= 0.2) {
away_from_e = false;
break;
}
}
if (away_from_e) recon_jets.push_back(jet);
}
// only keep electrons more than R=0.4 from jets
Particles recon_e;
for (const Particle& e : cand_e) {
bool away = true;
for (const Jet& jet : recon_jets) {
if (deltaR(e.momentum(), jet.momentum()) < 0.4) {
away = false;
break;
}
}
if (away) recon_e.push_back(e);
}
// only keep muons more than R=0.4 from jets
Particles recon_mu;
for (const Particle& mu : cand_mu) {
bool away = true;
for (const Jet& jet : recon_jets) {
if (deltaR(mu.momentum(), jet.momentum()) < 0.4) {
away = false;
break;
}
}
if (away) recon_mu.push_back(mu);
}
// pTmiss
Particles vfs_particles = apply<VisibleFinalState>(event, "vfs").particles();
FourMomentum pTmiss;
for (const Particle& p : vfs_particles) {
pTmiss -= p.momentum();
}
double eTmiss = pTmiss.pT();
// now only use recon_jets, recon_mu, recon_e
// reject events with electrons and muons
if (!(recon_mu.empty() && recon_e.empty())) {
MSG_DEBUG("Charged leptons left after selection");
vetoEvent;
}
// calculate H_T
double HT = 0;
for (const Jet& jet : recon_jets) {
if (jet.pT() > 40 * GeV) HT += jet.pT();
}
// number of jets
unsigned int njet55 = 0, njet80 = 0;
for (unsigned int ix = 0; ix < recon_jets.size(); ++ix) {
if (recon_jets[ix].pT() > 80. * GeV) ++njet80;
if (recon_jets[ix].pT() > 55. * GeV) ++njet55;
}
if (njet55 == 0) vetoEvent;
double ratio = eTmiss / sqrt(HT);
if (ratio > 4.) {
_hist_njet55->fill(njet55);
_hist_njet80->fill(njet80);
// 7j55
if (njet55 >= 7) _count_7j55->fill(0.5);
// 8j55
if (njet55 >= 8) _count_8j55->fill(0.5);
// 8j55
if (njet55 >= 9) _count_9j55->fill(0.5);
// 6j80
if (njet80 >= 6) _count_6j80->fill(0.5);
// 7j80
if (njet80 >= 7) _count_7j80->fill(0.5);
// 8j80
if (njet80 >= 8) _count_8j80->fill(0.5);
}
if (njet55 >= 7) _etmiss_HT_7j55->fill(ratio);
// 8j55
if (njet55 >= 8) _etmiss_HT_8j55->fill(ratio);
// 8j55
if (njet55 >= 9) _etmiss_HT_9j55->fill(ratio);
// 6j80
if (njet80 >= 6) _etmiss_HT_6j80->fill(ratio);
// 7j80
if (njet80 >= 7) _etmiss_HT_7j80->fill(ratio);
// 8j80
if (njet80 >= 8) _etmiss_HT_8j80->fill(ratio);
}
/// @}
void finalize() {
double norm = crossSection() / femtobarn * 4.7 / sumOfWeights();
scale(_etmiss_HT_7j55, 2. * norm);
scale(_etmiss_HT_8j55, 2. * norm);
scale(_etmiss_HT_9j55, 2. * norm);
scale(_etmiss_HT_6j80, 2. * norm);
scale(_etmiss_HT_7j80, 2. * norm);
scale(_etmiss_HT_8j80, 2. * norm);
scale(_hist_njet55, norm);
scale(_hist_njet80, norm);
scale(_count_7j55, norm);
scale(_count_8j55, norm);
scale(_count_9j55, norm);
scale(_count_6j80, norm);
scale(_count_7j80, norm);
scale(_count_8j80, norm);
}
private:
/// @name Histograms
/// @{
Histo1DPtr _etmiss_HT_7j55;
Histo1DPtr _etmiss_HT_8j55;
Histo1DPtr _etmiss_HT_9j55;
Histo1DPtr _etmiss_HT_6j80;
Histo1DPtr _etmiss_HT_7j80;
Histo1DPtr _etmiss_HT_8j80;
Histo1DPtr _hist_njet55;
Histo1DPtr _hist_njet80;
Histo1DPtr _count_7j55;
Histo1DPtr _count_8j55;
Histo1DPtr _count_9j55;
Histo1DPtr _count_6j80;
Histo1DPtr _count_7j80;
Histo1DPtr _count_8j80;
/// @}
};
RIVET_DECLARE_PLUGIN(ATLAS_2012_I1117704);
}