Rivet analyses

title: ATLAS_2016_I1452559

Monojet + missing energy search with 3.2/fb of 13 TeV $pp$ data

Experiment: ATLAS (LHC)

Inspire ID: 1452559

Status: UNVALIDATED

Authors: - Andy Buckley - Shehu AbdusSalam

References: - Expt page: ATLAS-EXOT-2015-03 - Phys.Rev. D94 (2016) no.3, 032005 - DOI: 10.1103/PhysRevD.94.032005 - CERN-EP-2016-075 - arXiv: 1604.07773

Beams: p+ p+

Beam energies: (6500.0, 6500.0)GeV

Run details: - BSM signal events

A search for new phenomena in final states with an energetic jet and large missing transverse momentum. The search uses proton-proton collision data corresponding to an integrated luminosity of 3.2/fb of $pp$ collisions at 13~\TeV, collected in 2015 with the ATLAS detector. Events are required to have at least one jet with a transverse momentum above 250 GeV and no leptons. Several signal regions are considered with increasing missing-transverse-momentum requirements between $E_T^\mathrm{miss} > 250~\GeV$ and 700~\GeV. Good agreement is observed between the number of events in data and Standard Model predictions.

Source code:ATLAS_2016_I1452559.cc

```c++

include "Rivet/Analysis.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/IdentifiedFinalState.hh"

include "Rivet/Projections/MissingMomentum.hh"

include "Rivet/Projections/SmearedJets.hh"

include "Rivet/Projections/SmearedMET.hh"

include "Rivet/Projections/SmearedParticles.hh"

include "Rivet/Projections/VisibleFinalState.hh"

namespace Rivet {

/// ATLAS 13 TeV monojet search with 3.2/fb of pp data class ATLAS_2016_I1452559 : public Analysis { public:

RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2016_I1452559);

void init() {

  FastJets jets(FinalState(Cuts::abseta < 4.9), JetAlg::ANTIKT, 0.4);
  SmearedJets recojets(jets, JET_SMEAR_ATLAS_RUN1);
  declare(recojets, "Jets");

  FinalState electrons(Cuts::abspid == PID::ELECTRON && Cuts::abseta < 2.47 && Cuts::pT > 20 * GeV);
  SmearedParticles recoelectrons(electrons, ELECTRON_EFF_ATLAS_RUN1_MEDIUM);
  declare(recoelectrons, "Electrons");

  FinalState muons(Cuts::abspid == PID::MUON && Cuts::abseta < 2.50 && Cuts::pT > 10 * GeV);
  SmearedParticles recomuons(muons, MUON_EFF_ATLAS_RUN1);
  declare(recomuons, "Muons");

  VisibleFinalState calofs(Cuts::abseta < 4.9 && Cuts::abspid != PID::MUON);
  MissingMomentum met(calofs);
  SmearedMET recomet(met, MET_SMEAR_ATLAS_RUN1);
  declare(recomet, "MET");


  /// Book histograms
  for (size_t i = 0; i < 7; ++i) book(_count_IM[i], "count_IM" + toString(i + 1));
  for (size_t i = 0; i < 6; ++i) book(_count_EM[i], "count_EM" + toString(i + 1));
}


void analyze(const Event& event) {

  const Jets jets = apply<JetFinder>(event, "Jets").jetsByPt(Cuts::pT > 20 * GeV && Cuts::abseta < 2.8);
  const Particles elecs = apply<ParticleFinder>(event, "Electrons").particlesByPt();
  const Particles mus = apply<ParticleFinder>(event, "Muons").particlesByPt();
  MSG_DEBUG("Number of raw jets, electrons, muons = " << jets.size() << ", " << elecs.size() << ", "
                                                      << mus.size());

  // Discard jets very close to electrons, or with low track multiplicity and close to muons
  const Jets isojets = discard(jets, [&](const Jet& j) {
    /// @todo Add track efficiency random filtering
    if (any(elecs, deltaRLess(j, 0.2))) return true;
    if (j.particles(Cuts::abscharge > 0 && Cuts::pT > 0.4 * GeV).size() < 3
        && any(mus, deltaRLess(j, 0.4)))
      return true;
    return false;
  });

  // Discard electrons close to remaining jets
  const Particles isoelecs = discard(elecs,
                                     [&](const Particle& e) { return any(isojets, deltaRLess(e, 0.4)); });

  // Discard muons close to remaining jets
  const Particles isomus = discard(mus, [&](const Particle& m) {
    for (const Jet& j : isojets) {
      if (deltaR(j, m) > 0.4) continue;
      if (j.particles(Cuts::abscharge > 0 && Cuts::pT > 0.4 * GeV).size() > 3) return true;
    }
    return false;
  });

  // Calculate ETmiss
  //const Vector3& vet = apply<MissingMomentum>(event, "MET").vectorEt();
  const Vector3& vet = apply<SmearedMET>(event, "MET").vectorEt();
  const double etmiss = vet.perp();


  // Event selection cuts
  if (etmiss < 250 * GeV) vetoEvent;
  // Require at least one jet with pT > 250 GeV and |eta| < 2.4
  if (select(isojets, Cuts::pT > 250 * GeV && Cuts::abseta < 2.4).empty()) vetoEvent;
  // Require at most 4 jets with pT > 30 GeV and |eta| < 2.8
  if (select(isojets, Cuts::pT > 30 * GeV).size() > 4) vetoEvent;
  // Require no isolated jets within |dphi| < 0.4 of the MET vector
  if (any(isojets, deltaPhiLess(-vet, 0.4))) vetoEvent;
  // Require no isolated electrons or muons
  if (!isoelecs.empty() || !isomus.empty()) vetoEvent;


  ////////////////////


  // Get ETmiss bin number and fill counters
  const int i_etmiss = binIndex(etmiss / GeV, ETMISS_CUTS);
  // Inclusive ETmiss bins
  for (int ibin = 0; ibin < 7; ++ibin)
    if (i_etmiss >= ibin) _count_IM[ibin]->fill();
  // Exclusive ETmiss bins
  if (inRange(i_etmiss, 0, 6)) _count_EM[i_etmiss]->fill();
}


void finalize() {
  const double norm = 3.2 * crossSection() / femtobarn;
  scale(_count_IM, norm / sumOfWeights());
  scale(_count_EM, norm / sumOfWeights());
}

private:

const vector<double> ETMISS_CUTS = {250, 300, 350, 400, 500, 600, 700, 13000};
CounterPtr _count_IM[7], _count_EM[6];

};

RIVET_DECLARE_PLUGIN(ATLAS_2016_I1452559);

} ```