Rivet analyses

title: ATLAS_2012_I1082009

$D^{*\pm}$ production in jets

Experiment: ATLAS (LHC)

Inspire ID: 1082009

Status: VALIDATED

Authors: - Peter Richardson

References: - arXiv: 1112.4432

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - All flavours of quark and gluon jet production at 7 TeV

Measurement of $D^{*\pm}$ meson production in jets from proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=7$ TeV at the LHC. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of $0.30\,\text{pb}^{-1}$ for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range $|eta| < 2.5$.

Source code:ATLAS_2012_I1082009.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/IdentifiedFinalState.hh"

include "Rivet/Projections/LeadingParticlesFinalState.hh"

include "Rivet/Projections/MissingMomentum.hh"

include "Rivet/Projections/UnstableParticles.hh"

include "Rivet/Projections/VetoedFinalState.hh"

namespace Rivet {

class ATLAS_2012_I1082009 : public Analysis { public:

/// @name Constructors etc.
/// @{

/// Constructor
ATLAS_2012_I1082009()
    : Analysis("ATLAS_2012_I1082009") { }

/// @}

public:

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

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

  // Input for the jets: No neutrinos, no muons
  VetoedFinalState veto;
  veto.addVetoPairId(PID::MUON);
  veto.vetoNeutrinos();
  FastJets jets(veto, JetAlg::ANTIKT, 0.6);
  declare(jets, "jets");
  // unstable final-state for D*
  declare(UnstableParticles(), "UFS");

  book(_weight25_30, "_weight_25_30");
  book(_weight30_40, "_weight_30_40");
  book(_weight40_50, "_weight_40_50");
  book(_weight50_60, "_weight_50_60");
  book(_weight60_70, "_weight_60_70");
  book(_weight25_70, "_weight_25_70");

  book(_h_pt25_30, 8, 1, 1);
  book(_h_pt30_40, 9, 1, 1);
  book(_h_pt40_50, 10, 1, 1);
  book(_h_pt50_60, 11, 1, 1);
  book(_h_pt60_70, 12, 1, 1);
  book(_h_pt25_70, 13, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // get the jets
  Jets jets = apply<FastJets>(event, "jets").jetsByPt(Cuts::pT > 25 * GeV && Cuts::abseta < 2.5);
  // get the D* mesons
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  Particles Dstar;
  for (const Particle& p : ufs.particles()) {
    const int id = p.abspid();
    if (id == 413) Dstar.push_back(p);
  }

  // loop over the jobs
  for (const Jet& jet : jets) {
    double perp = jet.perp();
    bool found = false;
    double z(0.);
    if (perp < 25. || perp > 70.) continue;
    for (const Particle& p : Dstar) {
      if (p.perp() < 7.5) continue;
      if (deltaR(p, jet.momentum()) < 0.6) {
        Vector3 axis = jet.p3().unit();
        z = axis.dot(p.p3()) / jet.E();
        if (z < 0.3) continue;
        found = true;
        break;
      }
    }
    _weight25_70->fill();
    if (found) _h_pt25_70->fill(z);
    if (perp >= 25. && perp < 30.) {
      _weight25_30->fill();
      if (found) _h_pt25_30->fill(z);
    }
    else if (perp >= 30. && perp < 40.) {
      _weight30_40->fill();
      if (found) _h_pt30_40->fill(z);
    }
    else if (perp >= 40. && perp < 50.) {
      _weight40_50->fill();
      if (found) _h_pt40_50->fill(z);
    }
    else if (perp >= 50. && perp < 60.) {
      _weight50_60->fill();
      if (found) _h_pt50_60->fill(z);
    }
    else if (perp >= 60. && perp < 70.) {
      _weight60_70->fill();
      if (found) _h_pt60_70->fill(z);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_pt25_30, 1. / *_weight25_30);
  scale(_h_pt30_40, 1. / *_weight30_40);
  scale(_h_pt40_50, 1. / *_weight40_50);
  scale(_h_pt50_60, 1. / *_weight50_60);
  scale(_h_pt60_70, 1. / *_weight60_70);
  scale(_h_pt25_70, 1. / *_weight25_70);
}

/// @}

private:

/// @name Histograms
/// @{
CounterPtr _weight25_30, _weight30_40, _weight40_50;
CounterPtr _weight50_60, _weight60_70, _weight25_70;

Histo1DPtr _h_pt25_30;
Histo1DPtr _h_pt30_40;
Histo1DPtr _h_pt40_50;
Histo1DPtr _h_pt50_60;
Histo1DPtr _h_pt60_70;
Histo1DPtr _h_pt25_70;
/// @}

};

RIVET_DECLARE_PLUGIN(ATLAS_2012_I1082009);

} ```