Rivet analyses

title: ATLAS_2012_CONF_2012_103

High jet-multiplicity + MET squark and gluino search

Experiment: ATLAS (LHC)

Inspire ID: 1204314

Status: OBSOLETE

Authors: - Peter Richardson

References: - Expt page: ATLAS-CONF-2012-103 - arXiv: 1206.1760

Beams: p+ p+

Beam energies: (4000.0, 4000.0)GeV

Run details: - BSM signal events at 8000 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 8 TeV. The data sample has a total integrated luminosity of 5.8 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. The analysis is identical to the previous 7 TeV paper.

Source code:ATLAS_2012_CONF_2012_103.cc

```c++ // -- 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_CONF_2012_103 : public Analysis { public:

/// Constructor
ATLAS_2012_CONF_2012_103()
    : Analysis("ATLAS_2012_CONF_2012_103") { }


/// @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");

  /// 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", 4, 5.5, 9.5);
  book(_hist_njet80, "hist_njet80", 4, 4.5, 8.5);

  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 * GeV && Cuts::abseta < 2.8);

  // candidate muons
  Particles cand_mu = apply<IdentifiedFinalState>(event, "muons").particlesByPt();

  // 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;
  }

  double ratio = eTmiss / sqrt(HT);

  if (ratio > 4.) {
    if (njet55 > 9) njet55 = 9;
    if (njet80 > 8) njet80 = 8;
    _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 * 5.8 / 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_CONF_2012_103);

} ```