Rivet analyses

Single-lepton search for supersymmetry

Experiment: ATLAS (LHC)

Inspire ID: 930005

Status: OBSOLETE

Authors: none listed

References: - Expt page: ATLAS-SUSY-2011-08 - Phys. Rev.D85:012006,2012 - arXiv: 1109.6606

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - BSM signal events at 7000 GeV.

Single lepton search for supersymmmetric particles by ATLAS at 7 TeV. Event counts in electron and muon signal regions are implemented as one-bin histograms. Histograms for missing transverse energy and effective mass are implemented for the two signal regions.

Source code:ATLAS_2011_I930005.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"

namespace Rivet {


  /// Single-lepton search for supersymmetry
  class ATLAS_2011_I930005 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_I930005);


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

    /// Book histograms and initialize 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");


      // veto region electrons (from 2010 arXiv:1102.2357v2)
      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 muons
      IdentifiedFinalState muons(Cuts::abseta < 2.4 && Cuts::pT > 10 * GeV);
      muons.acceptIdPair(PID::MUON);
      declare(muons, "muons");


      // Jet finder
      VetoedFinalState vfs;
      vfs.addVetoPairId(PID::MUON);
      declare(FastJets(vfs, JetAlg::ANTIKT, 0.4), "AntiKtJets04");


      // all tracks (to do deltaR with leptons)
      declare(ChargedFinalState(Cuts::abseta < 3 && Cuts::pT > 0.5 * GeV), "cfs");


      // for pTmiss
      declare(VisibleFinalState(Cuts::abseta < 4.5), "vfs");


      /// Book histograms
      book(_3jl_count_mu_channel, "3jl_count_muon_channel", 1, 0., 1.);
      book(_3jl_count_e_channel, "3jl_count_electron_channel", 1, 0., 1.);
      book(_3jt_count_mu_channel, "3jt_count_muon_channel", 1, 0., 1.);
      book(_3jt_count_e_channel, "3jt_count_electron_channel", 1, 0., 1.);
      book(_3j_hist_eTmiss_e, "3j_Et_miss_e", 65, 0., 650.);
      book(_3j_hist_eTmiss_mu, "3j_Et_miss_mu", 65, 0., 650.);
      book(_3j_hist_mT_e, "3j_mT_e", 58, 0., 580.);
      book(_3j_hist_mT_mu, "3j_mT_mu", 58, 0., 580.);
      book(_3j_hist_m_eff_e, "3j_m_eff_e", 46, 0., 2300.);
      book(_3j_hist_m_eff_mu, "3j_m_eff_mu", 46, 0., 2300.);
      book(_3jl_hist_m_eff_e_final, "3jl_m_eff_e_final", 15, 0., 1500.);
      book(_3jl_hist_m_eff_mu_final, "3jl_m_eff_mu_final", 15, 0., 1500.);
      book(_3jt_hist_m_eff_e_final, "3jt_m_eff_e_final", 15, 0., 1500.);
      book(_3jt_hist_m_eff_mu_final, "3jt_m_eff_mu_final", 15, 0., 1500.);


      book(_4jl_count_mu_channel, "4jl_count_muon_channel", 1, 0., 1.);
      book(_4jl_count_e_channel, "4jl_count_electron_channel", 1, 0., 1.);
      book(_4jt_count_mu_channel, "4jt_count_muon_channel", 1, 0., 1.);
      book(_4jt_count_e_channel, "4jt_count_electron_channel", 1, 0., 1.);
      book(_4j_hist_eTmiss_e, "4j_Et_miss_e", 65, 0., 650.);
      book(_4j_hist_eTmiss_mu, "4j_Et_miss_mu", 65, 0., 650.);
      book(_4j_hist_mT_e, "4j_mT_e", 58, 0., 580.);
      book(_4j_hist_mT_mu, "4j_mT_mu", 58, 0., 580.);
      book(_4j_hist_m_eff_e, "4j_m_eff_e", 46, 0., 2300.);
      book(_4j_hist_m_eff_mu, "4j_m_eff_mu", 46, 0., 2300.);
      book(_4jl_hist_m_eff_e_final, "4jl_m_eff_e_final", 15, 0., 1500.);
      book(_4jl_hist_m_eff_mu_final, "4jl_m_eff_mu_final", 15, 0., 1500.);
      book(_4jt_hist_m_eff_e_final, "4jt_m_eff_e_final", 15, 0., 1500.);
      book(_4jt_hist_m_eff_mu_final, "4jt_m_eff_mu_final", 15, 0., 1500.);
    }


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

      Jets cand_jets = apply<FastJets>(event, "AntiKtJets04")
                           .jetsByPt(Cuts::pT > 20 * GeV && Cuts::abseta < 2.8);

      Particles candtemp_e = apply<IdentifiedFinalState>(event, "elecs").particlesByPt();
      Particles candtemp_mu = apply<IdentifiedFinalState>(event, "muons").particlesByPt();
      Particles chg_tracks = apply<ChargedFinalState>(event, "cfs").particles();
      Particles cand_mu;
      Particles cand_e;


      // pTcone around muon track
      for (const Particle& mu : candtemp_mu) {
        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);
      }

      // pTcone around electron
      for (const Particle& e : candtemp_e) {
        double pTinCone = -e.pT();
        for (const Particle& track : chg_tracks) {
          if (deltaR(e.momentum(), track.momentum()) < 0.2) pTinCone += track.pT();
        }
        if (pTinCone < 0.1 * e.pT()) cand_e.push_back(e);
      }

      // discard jets that overlap with electrons
      Jets recon_jets;
      for (const Jet& jet : cand_jets) {
        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 consider leptons far from jet
      Particles recon_e, recon_mu;
      for (const Particle& e : cand_e) {
        bool e_near_jet = false;
        for (const Jet& jet : recon_jets) {
          if (deltaR(e.momentum(), jet.momentum()) < 0.4 && deltaR(e.momentum(), jet.momentum()) > 0.2)
            e_near_jet = true;
        }
        if (!e_near_jet) recon_e.push_back(e);
      }

      for (const Particle& mu : cand_mu) {
        bool mu_near_jet = false;
        for (const Jet& jet : recon_jets) {
          if (deltaR(mu.momentum(), jet.momentum()) < 0.4) mu_near_jet = true;
        }
        if (!mu_near_jet) 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();


      // ==================== observables ====================


      // Njets
      int Njets = 0;
      double pTmiss_phi = pTmiss.phi();
      for (const Jet& jet : recon_jets) {
        if (jet.abseta() < 2.8) Njets += 1;
      }
      if (Njets < 3) {
        MSG_DEBUG("Only " << Njets << " jets w/ eta<2.8 left");
        vetoEvent;
      }

      Particles lepton;
      if (recon_mu.empty() && recon_e.empty()) {
        MSG_DEBUG("No leptons");
        vetoEvent;
      }
      else {
        for (const Particle& mu : recon_mu) lepton.push_back(mu);
        for (const Particle& e : recon_e) lepton.push_back(e);
      }


      std::sort(lepton.begin(), lepton.end(), cmpMomByPt);

      double e_id = 11;
      double mu_id = 13;

      // one hard leading lepton cut
      if (lepton[0].abspid() == e_id && lepton[0].pT() <= 25 * GeV) {
        vetoEvent;
      }
      else if (lepton[0].abspid() == mu_id && lepton[0].pT() <= 20 * GeV) {
        vetoEvent;
      }

      // exactly one hard leading lepton cut
      if (lepton.size() > 1) {
        if (lepton[1].abspid() == e_id && lepton[1].pT() > 20 * GeV) {
          vetoEvent;
        }
        else if (lepton[1].abspid() == mu_id && lepton[1].pT() > 10 * GeV) {
          vetoEvent;
        }
      }

      // 3JL
      if (recon_jets[0].pT() > 60.0 * GeV && recon_jets[1].pT() > 25.0 * GeV
          && recon_jets[2].pT() > 25.0 * GeV && deltaPhi(pTmiss_phi, recon_jets[0].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[1].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[2].phi()) > 0.2) {

        FourMomentum pT_l = lepton[0].momentum();
        double dPhi = deltaPhi(pT_l.phi(), pTmiss_phi);
        double mT = sqrt(2 * pT_l.pT() * eTmiss * (1 - cos(dPhi)));
        double m_eff = eTmiss + pT_l.pT() + recon_jets[0].pT() + recon_jets[1].pT() + recon_jets[2].pT();

        if (lepton[0].abspid() == e_id) {
          _3j_hist_mT_e->fill(mT);
          _3j_hist_eTmiss_e->fill(eTmiss);
          _3j_hist_m_eff_e->fill(m_eff);
          if (mT > 100 * GeV && eTmiss > 125 * GeV) {
            _3jl_hist_m_eff_e_final->fill(m_eff);
            if (m_eff > 500 * GeV && eTmiss > 0.25 * m_eff) {
              _3jl_count_e_channel->fill(0.5);
            }
          }
        }

        else if (lepton[0].abspid() == mu_id) {
          _3j_hist_mT_mu->fill(mT);
          _3j_hist_eTmiss_mu->fill(eTmiss);
          _3j_hist_m_eff_mu->fill(m_eff);
          if (mT > 100 * GeV && eTmiss > 125 * GeV) {
            _3jl_hist_m_eff_mu_final->fill(m_eff);
            if (m_eff > 500 * GeV && eTmiss > 0.25 * m_eff) {
              _3jl_count_mu_channel->fill(0.5);
            }
          }
        }
      }

      // 3JT
      if (recon_jets[0].pT() > 80.0 * GeV && recon_jets[1].pT() > 25.0 * GeV
          && recon_jets[2].pT() > 25.0 * GeV && deltaPhi(pTmiss_phi, recon_jets[0].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[1].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[2].phi()) > 0.2) {

        FourMomentum pT_l = lepton[0].momentum();
        double dPhi = deltaPhi(pT_l.phi(), pTmiss_phi);
        double mT = sqrt(2 * pT_l.pT() * eTmiss * (1 - cos(dPhi)));
        double m_eff = eTmiss + pT_l.pT() + recon_jets[0].pT() + recon_jets[1].pT() + recon_jets[2].pT();


        if (lepton[0].abspid() == e_id) {
          if (mT > 100 * GeV && eTmiss > 240 * GeV) {
            _3jt_hist_m_eff_e_final->fill(m_eff);
            if (m_eff > 600 * GeV && eTmiss > 0.15 * m_eff) {
              _3jt_count_e_channel->fill(0.5);
            }
          }
        }

        else if (lepton[0].abspid() == mu_id) {
          if (mT > 100 * GeV && eTmiss > 240 * GeV) {
            _3jt_hist_m_eff_mu_final->fill(m_eff);
            if (m_eff > 600 * GeV && eTmiss > 0.15 * m_eff) {
              _3jt_count_mu_channel->fill(0.5);
            }
          }
        }
      }

      if (Njets < 4) {
        MSG_DEBUG("Only " << Njets << " jets w/ eta<2.8 left");
        vetoEvent;
      }


      // 4JL
      if (recon_jets[0].pT() > 60.0 * GeV && recon_jets[1].pT() > 25.0 * GeV
          && recon_jets[2].pT() > 25.0 * GeV && recon_jets[3].pT() > 25.0 * GeV
          && deltaPhi(pTmiss_phi, recon_jets[0].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[1].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[2].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[3].phi()) > 0.2) {

        FourMomentum pT_l = lepton[0].momentum();
        double dPhi = deltaPhi(pT_l.phi(), pTmiss_phi);
        double mT = sqrt(2 * pT_l.pT() * eTmiss * (1 - cos(dPhi)));
        double m_eff = eTmiss + pT_l.pT() + recon_jets[0].pT() + recon_jets[1].pT() + recon_jets[2].pT()
            + recon_jets[3].pT();


        if (lepton[0].abspid() == e_id) {
          _4j_hist_mT_e->fill(mT);
          _4j_hist_eTmiss_e->fill(eTmiss);
          _4j_hist_m_eff_e->fill(m_eff);
          if (mT > 100 * GeV && eTmiss > 140 * GeV) {
            _4jl_hist_m_eff_e_final->fill(m_eff);
            if (m_eff > 300 * GeV && eTmiss > 0.3 * m_eff) {
              _4jl_count_e_channel->fill(0.5);
            }
          }
        }

        // Muon channel signal region
        else if (lepton[0].abspid() == mu_id) {
          _4j_hist_mT_mu->fill(mT);
          _4j_hist_eTmiss_mu->fill(eTmiss);
          _4j_hist_m_eff_mu->fill(m_eff);
          if (mT > 100 * GeV && eTmiss > 140 * GeV) {
            _4jl_hist_m_eff_mu_final->fill(m_eff);
            if (m_eff > 300 * GeV && eTmiss > 0.3 * m_eff) {
              _4jl_count_mu_channel->fill(0.5);
            }
          }
        }
      }

      // 4JT
      if (recon_jets[0].pT() > 60.0 * GeV && recon_jets[1].pT() > 40.0 * GeV
          && recon_jets[2].pT() > 40.0 * GeV && recon_jets[3].pT() > 40.0 * GeV
          && deltaPhi(pTmiss_phi, recon_jets[0].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[1].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[2].phi()) > 0.2
          && deltaPhi(pTmiss_phi, recon_jets[3].phi()) > 0.2) {

        FourMomentum pT_l = lepton[0].momentum();

        double m_eff = eTmiss + pT_l.pT() + recon_jets[0].pT() + recon_jets[1].pT() + recon_jets[2].pT()
            + recon_jets[3].pT();


        if (lepton[0].abspid() == e_id) {
          if (eTmiss > 200 * GeV) {
            _4jt_hist_m_eff_e_final->fill(m_eff);
            if (m_eff > 500 * GeV && eTmiss > 0.15 * m_eff) {
              _4jt_count_e_channel->fill(0.5);
            }
          }
        }

        // Muon channel signal region
        else if (lepton[0].abspid() == mu_id) {
          if (eTmiss > 200 * GeV) {
            _4jt_hist_m_eff_mu_final->fill(m_eff);
            if (m_eff > 500 * GeV && eTmiss > 0.15 * m_eff) {
              _4jt_count_mu_channel->fill(0.5);
            }
          }
        }
      }
    }

    /// @}


    void finalize() {

      scale(_3j_hist_eTmiss_e, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3j_hist_eTmiss_mu, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3j_hist_m_eff_e, 50. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3j_hist_m_eff_mu, 50. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3j_hist_mT_e, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3j_hist_mT_mu, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3jl_hist_m_eff_e_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3jl_hist_m_eff_mu_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3jt_hist_m_eff_e_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_3jt_hist_m_eff_mu_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());

      scale(_4j_hist_eTmiss_e, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4j_hist_eTmiss_mu, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4j_hist_m_eff_e, 50. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4j_hist_m_eff_mu, 50. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4j_hist_mT_e, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4j_hist_mT_mu, 10. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4jl_hist_m_eff_e_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4jl_hist_m_eff_mu_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4jt_hist_m_eff_e_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
      scale(_4jt_hist_m_eff_mu_final, 100. * 1.04e3 * crossSection() / picobarn / sumOfWeights());
    }

  private:

    /// @name Histograms
    /// @{
    Histo1DPtr _3jl_count_e_channel;
    Histo1DPtr _3jl_count_mu_channel;
    Histo1DPtr _3jt_count_e_channel;
    Histo1DPtr _3jt_count_mu_channel;
    Histo1DPtr _3j_hist_eTmiss_e;
    Histo1DPtr _3j_hist_eTmiss_mu;
    Histo1DPtr _3j_hist_m_eff_e;
    Histo1DPtr _3j_hist_m_eff_mu;
    Histo1DPtr _3j_hist_mT_e;
    Histo1DPtr _3j_hist_mT_mu;
    Histo1DPtr _3jl_hist_m_eff_e_final;
    Histo1DPtr _3jl_hist_m_eff_mu_final;
    Histo1DPtr _3jt_hist_m_eff_e_final;
    Histo1DPtr _3jt_hist_m_eff_mu_final;


    Histo1DPtr _4jl_count_e_channel;
    Histo1DPtr _4jl_count_mu_channel;
    Histo1DPtr _4jt_count_e_channel;
    Histo1DPtr _4jt_count_mu_channel;
    Histo1DPtr _4j_hist_eTmiss_e;
    Histo1DPtr _4j_hist_eTmiss_mu;
    Histo1DPtr _4j_hist_m_eff_e;
    Histo1DPtr _4j_hist_m_eff_mu;
    Histo1DPtr _4j_hist_mT_e;
    Histo1DPtr _4j_hist_mT_mu;
    Histo1DPtr _4jl_hist_m_eff_e_final;
    Histo1DPtr _4jl_hist_m_eff_mu_final;
    Histo1DPtr _4jt_hist_m_eff_e_final;
    Histo1DPtr _4jt_hist_m_eff_mu_final;
    /// @}
  };


  RIVET_DECLARE_ALIASED_PLUGIN(ATLAS_2011_I930005, ATLAS_2011_S9212353);

}

Aliases: - ATLAS_2011_S9212353