Rivet analyses

Experiment: ATLAS (LHC)

Inspire ID: 939504

Status: VALIDATED

Authors: - Peter Richardson

References: - Expt page: ATLAS-SUSY-2011-13 - arXiv: 1110.2299

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 1.34 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_2011_I939504.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 {


  /// High-jet-multiplicity squark and gluino search
  class ATLAS_2011_I939504 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_I939504);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {

      // veto region electrons
      Cut vetocut = Cuts::absetaIn(1.37, 1.52);
      IdentifiedFinalState veto_elecs(vetocut && Cuts::pT > 10 * GeV);
      veto_elecs.acceptIdPair(PID::ELECTRON);
      declare(veto_elecs, "veto_elecs");

      // 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(_etmisspT_55_NJ_6_obs, 1, 1, 1);
      book(_etmisspT_55_NJ_6_bac, 1, 1, 2);
      book(_etmisspT_55_NJ_6_sig, 1, 1, 3);
      book(_etmisspT_55_NJ_7_obs, 13, 1, 1);
      book(_etmisspT_55_NJ_7_bac, 13, 1, 2);
      book(_etmisspT_55_NJ_7_sig, 13, 1, 3);
      book(_etmisspT_55_NJ_8_obs, 15, 1, 1);
      book(_etmisspT_55_NJ_8_bac, 15, 1, 2);
      book(_etmisspT_55_NJ_8_sig, 15, 1, 3);
      book(_etmisspT_80_NJ_5_obs, 2, 1, 1);
      book(_etmisspT_80_NJ_5_bac, 2, 1, 2);
      book(_etmisspT_80_NJ_5_sig, 2, 1, 3);
      book(_etmisspT_80_NJ_6_obs, 14, 1, 1);
      book(_etmisspT_80_NJ_6_bac, 14, 1, 2);
      book(_etmisspT_80_NJ_6_sig, 14, 1, 3);
      book(_etmisspT_80_NJ_7_obs, 16, 1, 1);
      book(_etmisspT_80_NJ_7_bac, 16, 1, 2);
      book(_etmisspT_80_NJ_7_sig, 16, 1, 3);

      book(_njet55A_obs, 3, 1, 1);
      book(_njet55A_bac, 3, 1, 2);
      book(_njet55A_sig, 3, 1, 3);
      book(_njet55B_obs, 4, 1, 1);
      book(_njet55B_bac, 4, 1, 2);
      book(_njet55B_sig, 4, 1, 3);
      book(_njet55C_obs, 17, 1, 1);
      book(_njet55C_bac, 17, 1, 2);
      book(_njet55C_sig, 17, 1, 3);
      book(_njet80A_obs, 5, 1, 1);
      book(_njet80A_bac, 5, 1, 2);
      book(_njet80A_sig, 5, 1, 3);
      book(_njet80B_obs, 6, 1, 1);
      book(_njet80B_bac, 6, 1, 2);
      book(_njet80B_sig, 6, 1, 3);
      book(_njet80C_obs, 18, 1, 1);
      book(_njet80C_bac, 18, 1, 2);
      book(_njet80C_sig, 18, 1, 3);

      book(_count_7j55, "count_7j55", 1, 0., 1.);
      book(_count_8j55, "count_8j55", 1, 0., 1.);
      book(_count_6j80, "count_6j80", 1, 0., 1.);
      book(_count_7j80, "count_7j80", 1, 0., 1.);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // apply electron veto region
      Particles veto_e = apply<IdentifiedFinalState>(event, "veto_elecs").particles();
      if (!veto_e.empty()) {
        MSG_DEBUG("electrons in veto region");
        vetoEvent;
      }

      // get the jet candidates
      Jets cand_jets = apply<FastJets>(event, "AntiKtJets04")
                           .jetsByPt(Cuts::pT > 20.0 * GeV && Cuts::abseta < 4.9);

      // 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 cand_jets_2;
      for (const Jet& jet : cand_jets) {
        // candidates above eta=2.8 are jets
        if (fabs(jet.eta()) >= 2.8) cand_jets_2.push_back(jet);
        // otherwise more the R=0.2 from an electrons
        else {
          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) cand_jets_2.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 : cand_jets_2) {
          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 : cand_jets_2) {
          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();

      // final jet filter
      Jets recon_jets;
      for (const Jet& jet : cand_jets_2) {
        if (jet.abseta() <= 2.8) recon_jets.push_back(jet);
      }

      // 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 and deltaR
      bool pass55DeltaR = true, pass80DeltaR = true;
      size_t njet55 = 0, njet80 = 0;
      for (size_t ix = 0; ix < recon_jets.size(); ++ix) {
        if (recon_jets[ix].pT() > 80 * GeV) ++njet80;
        if (recon_jets[ix].pT() > 55 * GeV) ++njet55;
        for (size_t iy = ix + 1; iy < recon_jets.size(); ++iy) {
          if (recon_jets[ix].pT() > 55 * GeV && recon_jets[iy].pT() > 55 * GeV
              && deltaR(recon_jets[ix], recon_jets[iy]) < 0.6)
            pass55DeltaR = false;
          // if (recon_jets[ix].pT() > 80*GeV &&
          //     recon_jets[iy].pT() > 80*GeV &&
          //     deltaR(recon_jets[ix], recon_jets[iy]) < 0.6)
          //   pass80DeltaR = false;
        }
      }

      // require at least four jets with et > 55
      if (njet55 <= 3) vetoEvent;

      // plots of etmiss/ht
      double etht = eTmiss / sqrt(HT);
      if (njet55 == 6) {
        _etmisspT_55_NJ_6_obs->fill(etht);
        _etmisspT_55_NJ_6_bac->fill(etht);
        _etmisspT_55_NJ_6_sig->fill(etht);
      }
      else if (njet55 == 7) {
        _etmisspT_55_NJ_7_obs->fill(etht);
        _etmisspT_55_NJ_7_bac->fill(etht);
        _etmisspT_55_NJ_7_sig->fill(etht);
      }
      else if (njet55 == 8) {
        _etmisspT_55_NJ_8_obs->fill(etht);
        _etmisspT_55_NJ_8_bac->fill(etht);
        _etmisspT_55_NJ_8_sig->fill(etht);
      }
      if (njet80 == 5) {
        _etmisspT_80_NJ_5_obs->fill(etht);
        _etmisspT_80_NJ_5_bac->fill(etht);
        _etmisspT_80_NJ_5_sig->fill(etht);
      }
      else if (njet80 == 6) {
        _etmisspT_80_NJ_6_obs->fill(etht);
        _etmisspT_80_NJ_6_bac->fill(etht);
        _etmisspT_80_NJ_6_sig->fill(etht);
      }
      else if (njet80 == 7) {
        _etmisspT_80_NJ_7_obs->fill(etht);
        _etmisspT_80_NJ_7_bac->fill(etht);
        _etmisspT_80_NJ_7_sig->fill(etht);
      }

      if (etht > 1.5 && etht < 2.) {
        if (njet55 > 3) {
          _njet55A_obs->fill(njet55);
          _njet55A_bac->fill(njet55);
          _njet55A_sig->fill(njet55);
        }
        if (njet80 > 3) {
          _njet80A_obs->fill(njet80);
          _njet80A_bac->fill(njet80);
          _njet80A_sig->fill(njet80);
        }
      }
      else if (etht > 2. && etht < 3.) {
        if (njet55 > 3) {
          _njet55B_obs->fill(njet55);
          _njet55B_bac->fill(njet55);
          _njet55B_sig->fill(njet55);
        }
        if (njet80 > 3) {
          _njet80B_obs->fill(njet80);
          _njet80B_bac->fill(njet80);
          _njet80B_sig->fill(njet80);
        }
      }
      else {
        if (njet55 > 3) {
          _njet55C_obs->fill(njet55);
          _njet55C_bac->fill(njet55);
          _njet55C_sig->fill(njet55);
        }
        if (njet80 > 3) {
          _njet80C_obs->fill(njet80);
          _njet80C_bac->fill(njet80);
          _njet80C_sig->fill(njet80);
        }
      }

      // apply E_T/sqrt(H_T) cut
      if (etht <= 3.5 * GeV) {
        MSG_DEBUG("Fails ET/sqrt(HT) cut ");
        vetoEvent;
      }

      // check passes at least one delta5/ njet number cut
      if (!(pass55DeltaR && njet55 >= 7) && !(pass80DeltaR && njet80 >= 6)) {
        MSG_DEBUG("Fails DeltaR cut or jet number cuts");
        vetoEvent;
      }

      // 7j55
      if (njet55 >= 7 && pass55DeltaR) _count_7j55->fill(0.5);
      // 8j55
      if (njet55 >= 8 && pass55DeltaR) _count_8j55->fill(0.5);
      // 6j80
      if (njet80 >= 6 && pass80DeltaR) _count_6j80->fill(0.5);
      // 7j80
      if (njet80 >= 7 && pass80DeltaR) _count_7j80->fill(0.5);
    }

    /// @}

    void finalize() {
      const double norm = crossSection() / femtobarn * 1.34 / sumOfWeights();
      scale(_etmisspT_55_NJ_6_obs, norm);
      scale(_etmisspT_55_NJ_6_bac, norm);
      scale(_etmisspT_55_NJ_6_sig, norm);
      scale(_etmisspT_55_NJ_7_obs, norm);
      scale(_etmisspT_55_NJ_7_bac, norm);
      scale(_etmisspT_55_NJ_7_sig, norm);
      scale(_etmisspT_55_NJ_8_obs, norm);
      scale(_etmisspT_55_NJ_8_bac, norm);
      scale(_etmisspT_55_NJ_8_sig, norm);
      scale(_etmisspT_80_NJ_5_obs, norm);
      scale(_etmisspT_80_NJ_5_bac, norm);
      scale(_etmisspT_80_NJ_5_sig, norm);
      scale(_etmisspT_80_NJ_6_obs, norm);
      scale(_etmisspT_80_NJ_6_bac, norm);
      scale(_etmisspT_80_NJ_6_sig, norm);
      scale(_etmisspT_80_NJ_7_obs, norm);
      scale(_etmisspT_80_NJ_7_bac, norm);
      scale(_etmisspT_80_NJ_7_sig, norm);
      scale(_njet55A_obs, norm);
      scale(_njet55A_bac, norm);
      scale(_njet55A_sig, norm);
      scale(_njet55B_obs, norm);
      scale(_njet55B_bac, norm);
      scale(_njet55B_sig, norm);
      scale(_njet55C_obs, norm);
      scale(_njet55C_bac, norm);
      scale(_njet55C_sig, norm);
      scale(_njet80A_obs, norm);
      scale(_njet80A_bac, norm);
      scale(_njet80A_sig, norm);
      scale(_njet80B_obs, norm);
      scale(_njet80B_bac, norm);
      scale(_njet80B_sig, norm);
      scale(_njet80C_obs, norm);
      scale(_njet80C_bac, norm);
      scale(_njet80C_sig, norm);
      scale(_count_7j55, norm);
      scale(_count_8j55, norm);
      scale(_count_6j80, norm);
      scale(_count_7j80, norm);
    }

  private:

    /// @name Histograms
    /// @{
    Histo1DPtr _etmisspT_55_NJ_6_obs;
    Histo1DPtr _etmisspT_55_NJ_6_bac;
    Histo1DPtr _etmisspT_55_NJ_6_sig;
    Histo1DPtr _etmisspT_55_NJ_7_obs;
    Histo1DPtr _etmisspT_55_NJ_7_bac;
    Histo1DPtr _etmisspT_55_NJ_7_sig;
    Histo1DPtr _etmisspT_55_NJ_8_obs;
    Histo1DPtr _etmisspT_55_NJ_8_bac;
    Histo1DPtr _etmisspT_55_NJ_8_sig;
    Histo1DPtr _etmisspT_80_NJ_5_obs;
    Histo1DPtr _etmisspT_80_NJ_5_bac;
    Histo1DPtr _etmisspT_80_NJ_5_sig;
    Histo1DPtr _etmisspT_80_NJ_6_obs;
    Histo1DPtr _etmisspT_80_NJ_6_bac;
    Histo1DPtr _etmisspT_80_NJ_6_sig;
    Histo1DPtr _etmisspT_80_NJ_7_obs;
    Histo1DPtr _etmisspT_80_NJ_7_bac;
    Histo1DPtr _etmisspT_80_NJ_7_sig;
    Histo1DPtr _njet55A_obs;
    Histo1DPtr _njet55A_bac;
    Histo1DPtr _njet55A_sig;
    Histo1DPtr _njet55B_obs;
    Histo1DPtr _njet55B_bac;
    Histo1DPtr _njet55B_sig;
    Histo1DPtr _njet55C_obs;
    Histo1DPtr _njet55C_bac;
    Histo1DPtr _njet55C_sig;
    Histo1DPtr _njet80A_obs;
    Histo1DPtr _njet80A_bac;
    Histo1DPtr _njet80A_sig;
    Histo1DPtr _njet80B_obs;
    Histo1DPtr _njet80B_bac;
    Histo1DPtr _njet80B_sig;
    Histo1DPtr _njet80C_obs;
    Histo1DPtr _njet80C_bac;
    Histo1DPtr _njet80C_sig;
    Histo1DPtr _count_7j55;
    Histo1DPtr _count_8j55;
    Histo1DPtr _count_6j80;
    Histo1DPtr _count_7j80;
    /// @}
  };


  RIVET_DECLARE_ALIASED_PLUGIN(ATLAS_2011_I939504, ATLAS_2011_S9225137);

}

Aliases: - ATLAS_2011_S9225137